


Biting Off More Than You Can Chew

by keelywolfe



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Dubious Consent, First Time, Frenemies, M/M, Mating Cycles/In Heat, Spicyhoney - Freeform, Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underswap Papyrus (Undertale)
Language: English
Status: In-Progress
Published: 2018-10-28
Updated: 2019-05-23
Packaged: 2019-08-09 03:10:41
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 8
Words: 23,180
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16441883
Author URL: https://archiveofourown.org/users/keelywolfe/pseuds/keelywolfe
Summary: When Red asks Rus to look in on his sick brother, Rus agrees to stop by. Eh, it can’t hurt to help out a pal. Right?





	1. Chapter 1

**Author's Note:**

> This is a Heat story, so there are going to be issues of consent. I don’t do partner rape, nope, but hey, I want to be straight with y’all. I like heatfics personally, but I understand how they can be troubling for some people. So there it is. There is no explicit sex in this chapter. There will be eventually. There are some dubious consent-ish happenings.

* * *

It wasn't like Rus didn’t have his own damn job. Because he did, same as Red, he was a sentry, and sometimes he actually did some sentry-ing. Sometimes. Okay, so usually he was asleep at his station, but so what, he was there. And he should have told Red to fuck off from the beginning.

But eh, he liked Red. Guy had jokes, particularly of Rus's favorite variety: bad ones. So, when he texted asking Rus to check on his brother for him, he hadn't immediately said no.

**hey, man, my bro isn't feeling well and i can't get away. think you could stop and look in on him**

_can't get away? is that some kind of code name for this nap won't take itself? cause i speak fluent lazy and that's the translation i'm getting_

**fucking hilarious. seriously, he felt bad enough he actually stayed home and i'm doing his checks along with mine. i've got three traps to recalibrate and i just wanna make sure he's still kicking**

_with those boots of his? he could be in a chorus line, he's fine, quit squawking_

**please**

It was the please that got him. Context didn't exactly come through in a text message, but Rus knew Red well enough now that he could get a pretty clear picture at how grudging that word had been. He'd probably cracked the screen on his phone hammering it in.

It was with no little grudging of his own that he replied.

_you owe me_

**you bet. drinks are on me next time**

And okay, Rus was down with that. Red was not a guy to lie about his condiments and he'd better bring his big boy wallet because if he wanted Rus to check on Edge, he was going to be paying out for some serious drinks. 

Edge was…not his favorite person in the world.

For one, he was an asshole. Which normally wouldn't have disqualified him for the friendship circles and kum-ba-ya but it was the _way_ he was an asshole that got on Rus's metaphorical nerves. Hell, Red was an asshole, Rus had an appreciation for assholes that was normally reserved for purveyors of fine wines. 

Edge, on the other hand, was a complete jackhole and couldn't even bother to be funny about it. At least Papyrus was cheerful. Edge was a walking talking scourge on fucking enjoying life. Dealing with him in any capacity left Rus feeling raw and irritable and now Rus had the unprecedented joy of dealing with him while he was sick, which he was sure had left him in an oh, so charitable mood. 

Yeah, Red was going to owe him some serious drinks for this.

He considered sending Blue a text to let him know but, meh, this shouldn't take long and if Edge needed more than a quick check in and maybe some canned soup then he was out of Rus's area of expertise anyway. Whatever the equivalent of a doc was in Underfell had better be prepared for a house call.

Then again, their equivalent might be along the lines of handling a horse with a broken leg, so maybe not.

The machine powered on like a dream, seemingly pleased with their hours of sacrifice spent constantly repairing and cleaning. It was the one chore that Rus was honestly obsessive about. Now that he knew there were other universes around, other versions of him and his brother, well, maybe it was crazy but thinking about the machine breaking down again, of not being able to see the others, was enough to put him into a mild panic. The machine was an out, an escape for all of them.

Yeah, he wasn’t about to let that happen.

The rising electronic hum hit a crescendo and the portal spun into existence, a shimmery doorway of blackness. How much courage must it have taken for Sans to step through it for the first time? More than Rus fucking had, that was for sure. Or not courage, maybe something closer to desperation. That, at least, they’d all had at some point. In spades.

Weird that stepping through felt no different than walking into another room. Taking a shortcut could be weird and disorienting, a split-second through the void to get only as far around the corner. He’d spent years getting accustomed to it only to find out that traveling to another universe was easier than stopping at Muffet’s for a cookie.

The Fellverse brother’s basement was as neat and clean as his own, not that he believed Red had anything to do with it. The sterile worktable and gleaming metal had all the hallmarks of an obsessed Edgelord.

It was always interesting, from a scientific point of view anyway, the differences between their universes. Underfell was always a little darker, a little less. Supply lines were shaky and a trip to the dump to scavenge could have dire consequences.

It had taken him a little time, but once Blue had weaseled out that tidbit of trivia, little presents had started turning up for everyone at their weekly movie nights, even for Sans and Papyrus which was a neat way to keep Edge from shoving his ever-loving fucking pride up everyone’s asses. Couldn’t turn down a care packages of treats if _everyone_ was getting one, refusing to take a baggie of leftovers would be churlish when the host was setting them in _everyone_ ’s lap.

Blue knew how to steamroller over any prickly Fellverse pride with tender care that had the force of a sledgehammer. His bro was amazing, that was all Rus was saying and wasn’t that why he was really here? Blue would want him to come, would be disappointed if he’d refused, and Rus knew it.

The things he did for his bro.

Rus sighed to himself, itching for a cigarette before he had to face the asshole. Should’ve had a smoke for his nerves before he came, it wasn’t like he could step outside and light up. Shortcutting into the house was the general rule in all the ‘verses. For one, he wasn’t interested in spending too much time out in the open here and two, none of them wanted to try to explain a steady stream of strange skeletons coming to and fro from their basement. Not exactly discreet.

Better to get this over with. Rus took a step, two, and in between the second and the third, he took a shortcut that landed him in the Fell brother’s living room. The sight of it made him frown. Dirty dishes were scattered around, piled on the coffee table and even the floor. There were socks draped over the furniture and lying all over the place, like the peels of the world’s most disgusting fruit, and there was a weird smell in the air, something heavy and musty.

Okay, so maybe Red was right to be worried. Edge had to be really sick for their place to fall apart like this. A little cautiously, Rus checked the front door, but the rows of deadbolts were firmly locked. At least they didn’t have to worry about anyone breaking in. Probably.

Startling Edge was probably a quick way to land himself in a dust pan, so Rus called upstairs, “edge? hey, buddy, it’s just me, rus.”

No response.

That…that was not right. Edge was always on alert, always, (heh), on edge. Rus couldn’t imagine him not dragging himself to his feet if someone was in his house unless—

Ah, fuck.

Uncertainty was tossed out the metaphorical window and Rus went upstairs, not bothering to soften his footsteps. Their house was a mirror image of his own and the first door off the landing was Edge’s. With a deep breath, Rus braced himself and turned the knob to look inside.

The darkened bedroom was in the same state as the rest of the house, piled dishes, scattered clothes, and that smell was much stronger in here. Not unpleasant, exactly, Rus wasn’t sure he could describe it past _heavy_.

This was so weird.

His vision adjusted to the dark and Rus blinked, catching sight of a lump buried beneath the blankets on the bed. Worry wasn’t enough to overshadow his caution and Rus approached the bed, slowly. “edge?”

He didn’t stir, ah, fuck, that wasn’t good, he couldn’t imagine Edge letting anyone sneak up on him. A little panicked, Rus knelt by the bed, reaching out to shake him and by the stars, he couldn’t tell Red his brother was dying, fuck, he couldn’t—

Before he could actually touch the blankets, a strong hand caught him painfully by the wrist and Rus cried out, automatically trying to pull free. Uselessly, he couldn’t break that grip, couldn’t shortcut away and crimson eye lights lit in front of him, cutting through the dark.

“What are you doing here?” Edge’s normal cool voice was hardly more than a harsh croak.

“i…red asked me to check on you,” Rus blurted. He tried to pull free again, wincing as Edge’s grip didn’t loosen a fraction.

“You need to leave,” Edge shifted up to his elbow, the blankets slipping down to show a bare ribcage and sheets that were damp with sweat.

Rus laughed unevenly, “yep, that…that sounds great, love to leave and let you…uh…stay there…but you need to let me go first.”

No response, only those red eye lights, were…were they wider than normal? Rus thought they were, thought that Edge was breathing too heavily and there was that smell, so much stronger here, like a slap in the face with that heaviness, rich and overpowering and…what the _fuck_ was going on?

That thought was knocked out of him by the blur of movement dragging him along and Rus yelped as his shoulders hit the wall, staring in bewilderment at the face looming in front of his own. His wrist was pinned next to his head, his other hand pushing uselessly at Edge’s ribcage with as little effect as if he’d tried to shove over the house.

Edge was so close, leaning into him, his eye lights boring into Rus’s wide ones. He was only wearing a pair of shorts that hung so low on his pelvis he may as well be naked and the relief of him finally breaking that unblinking stare was broken by the wet, slick touch of a tongue against his collarbone as Edge ducked his head, tugging away his shirt to nuzzle at the bone beneath it.

“You need to leave,” Edge groaned hoarsely, even as he licked another wet stripe along the delicate bone.

“be…be easier if you let me go,” Rus choked out. His magic was starting to stir in a way that was more than a little unwelcome, that unknown smell was dizzyingly close. For one split-second of insanity, he almost leaned in closer, wanted to press his face against Edge’s downturned skull and inhale, and then -- ”what are you doi-ing!?”

The hard pressure of teeth settled against the bone and Rus squealed as Edge bit down, digging in deeply enough that he could feel a trickle of marrow running down into the collar of his sweatshirt. It _hurt_ , the pain clearing his head, and Rus struggled, fighting against Edge until he finally let loose. Dumbly, he watched as Edge licked his teeth clean, those wide, crimson eye lights meeting his own again.

There was still a smear of marrow clinging and dimly Rus registered that somehow his HP hadn’t dropped so much as a decimal point, how was that even possible, how was a fucking _bite_ not intent?

“You need to leave,” Edge said clearly. As if he wasn’t still holding Rus against a wall.

“yeah, i’m getting that vibe,” Rus said weakly. The bitemark on his collarbone throbbed and he reached up to touch it, felt the crust of the marrow already clotting.

Edge’s eye lights dilated to pinpricks, watching him, and abruptly he let Rus go, staggering back with a snarled, “Get out!”

The second Edge let him go, Rus did, shortcutting straight to the machine and through the portal like the hounds of hell were at his heels, like a hand might reach through the void somehow and snatch him back.

He staggered upstairs from his own basement, flinging the door open and sucking in deep breaths of the cold, Snowdin air. It cleared his head, dispersing the last, lingering traces of that smell, until Rus was left with nothing but his own confusion and a painful bite mark rubbing beneath his sweatshirt.

“assholes,” Rus muttered. Red and Edge both, didn't matter which. His hands were shaking, making him fumble as he tried to light a cigarette. It took too long for him to catch the tip in the wavering flame but after a couple puffs he was relaxing, steadying.

What the fuck had that all been about? Edge was an asshole, sure, but he was a prideful, stick-up-his-ass version, not whatever the hell that had been. And what had been up with that smell, he hadn’t even realized how dizzying it had been until he’d gotten away from it. Probably lucky he’d been able to shortcut at all. All of this was adding up to a lot of bullshit but fuck it, it wasn’t his bullshit; he’d been trying to be the nice guy, he was _supposed_ to be nicer than those Hellverse versions.

The bite ached, and Rus touched it, wincing. Okay, yeah, there was proof that he was the nicer one because even after that, he was worried about the shithead. None of this was exactly normal for a fucking cold or something. Rus lit another cigarette, inhaling deeply as he considered.

He could just text Red, let him know his brother had lost his everfucking mind, and let that be the end of it. But no, Red wasn’t his brother but…he also was, sort of, and he couldn’t let Red deal with whatever this was on his own.

Red probably wouldn’t be back from his rounds for a few hours yet. There was a little time for him to figure something out and Rus planned on using it on the one person who might be able to help him find answers.

 

TBC


	2. Chapter 2

**Summary for the Chapter:**

> Rus needs some answers and there is only one Monster in Underswap who might have them.

* * *

One of the weirder talents that Rus possessed had to be his knack of dump picking. The dump was hands down the best place to find unexpected treasures and Rus had honed the skill of finding them to a fine art. Racecar beds, broken televisions that he could repair, books and blu-rays, he found it all. Some of it was for Blue, most of it was for bartering because entertainment was worth a hell of a lot more than G on any day. The Underground was fucking boring, and that was a fact. 

With that in mind, he scavenged through his hidden stash of goods for some bribery material and luckily, he knew exactly he best kind. Hotland was only a quick shortcut away and in no time, Rus was standing at the laboratory door with his prize under his arm. 

Looking at the door made him feel a little queasy, though he wasn’t sure why; sure, he’d worked here for a little while but Snowdin was better for Blue when he’d been younger, plenty more Monsters his age, so they’d moved. That…he was pretty sure that was right, eh, didn’t matter, that was ages ago. Right now, he wanted some answers and the one person in Underswap who might be able to help was behind that door, hopefully.

He knocked, his knucklebones ringing loudly against the metal door. There was no answer and Rus knocked again even harder. He was kinda on a time crunch, here.

“c’mon, undyne, open up!” he called. “i know you’re in there, it’s not like you’re going to take a stroll around hotland! you know it’s me, i walked past four cameras just to get here.”

The door remained stubbornly closed. Rus sighed and readied his secret weapon, holding up the manga over his head where he knew a camera was looking down at him. “oh, no, whatever shall do with this holiday special double-length manga of mew mew kissy cutie, sixth edition,” he said flatly. 

He didn’t have to wait long after that. Slowly, the door creaked open and from the darkness within an eye peered out at him. “Papyrus?”

“hey, doll,” Rus said cheerfully, pushing firmly on the door and ignoring Undyne’s squawk as he strode in. “how’s things? still determined to stay in the old lab, huh? i ain’t judging, but you’re nuts to stay in a place where stepping outside could turn you into fish sticks. speaking of which, might want to close the door, you're letting the ungodly fires of hell in.”

“w-what are you doing here?” Undyne closed the door and then didn’t seem to know what to do, only standing by it, wringing her hands. 

Time to put some of that charm of his to work. “okay, i know, we haven’t talked in person in like…a while. sorry about that,” Rus said, with all the gentle apology he could. It was true; once they’d been colleagues but Undyne kept to herself in the lab. After he’d quit, there had been no reason to come here and it wasn’t like she was gonna stop by Muffet’s for a pastry and a beer after work. Still, he was in Hotland all the time, one of his sentry posts wasn’t far away, he could have stopped by…but this place was so fucking creepy. The overhead lights were glaring down at them, and all the cameras on the nearby workstation were posed all over Underswap, the camera feed looping, spying. Even if he understood why, it was still creepy. He’d have to think about it. 

“N-no, it’s all right, Papyrus!” Undyne shook her head, her messy red hair falling over her shoulders. “You didn’t have to come here anymore.”

“yeah, maybe, but we’re still friends, right?” he coaxed, “we chat on the undernet all the time, yeah? and i ain’t gonna lie, i didn’t just come over to give you this.” He held up the manga and her eyes strayed to it as he waved it enticingly, a reminder of what was at stake. “i need a favor. you know more about monster anatomy than anyone. so, do you know much about Monster sicknesses?” 

“Is Sans...all right?” She gave him a worried look, biting her lip, and her eyes found anything to look at but him, “Um, is it a-about falling down?"

"nah, geez, nothing like that!” Rus exclaimed, aghast. Fuck, he hoped it was nothing like that. “it’s just something i heard about, something...weird."

She nodded, wary, but maybe hinting towards curious. "What kind of weird?"

"Like…what kind of sickness would make a monster hot and sweaty but without a fever. aggressive." he did not raise his hand to his collarbone. "kind of…bitey."

To his surprise, her expression soured. “That's not, hm, funny."

"i'm not kidding and you're right, it's not,” Rus said slowly. He squinted at her. “you have any ideas?"

She still looked doubtful, shuffling her feet against the hard tiles of the floor, daring to look back up at him with something almost like a challenge, “If you’ve been reading old journals just to mess with me—"

“undyne, you know i wouldn’t mess with you, not like that. you know that, right?” She lowered her eyes and nodded. “okay, so what do you mean old journals?”

She still seemed a little uncertain and Rus gave her a beseeching look, turning on the wide eye lights that worked so well on Blue when it came to a second dessert. Apparently, they had an affect on fish monsters too because Undyne sighed a little and gestured at him.

“C-come on,” Undyne slouched into the lab and Rus followed, shaking away his uneasiness. This place was creepy as fuck even without the cups of dried ramen scattered all over, and laundry scattered around. Seemed like it was his fate today to walk through the realms of the slobs. Blue would be having a conniption if he saw this.

It was worse the further they went, dust layering everything, and just as he was starting to wonder if this was a secret plot to mug him for the manga and lock him up for some quality ‘science’, Undyne led him to a darkened room. She flipped on a switch with a loud click and bright fluorescents came on overhead, humming loudly, which was a good thing because he wasn’t about to go into the creepy fucking lab room in the dark. Edge would have had to start looking into those Underfell horse doctors and hope they didn’t shoot first and ask questions later. 

The room was mostly empty, the only furniture was one bookshelf loaded with heavy tomes, and Undyne squatted next to it, hesitating over each one until she made a satisfied sound and pulled one free. She settled to sit on the dusty floor and Rus sat next to her, leaning in curiously. She held it out to him, “Here, look.

“regulatory hypothalamic estrus response in monsters due stagnating populaces,” he read slowly. “sounds like a real page-turner. okay, what is it?”

“It’s an e-evolutionary holdover,” she explained, opening the book, “to help maintain Monster populations. M-monsters reproduce slowly compared to some other species, and if our numbers ever drop low enough, the effect can be a hormonal response in our magic that stimulates estrus or heat.”

“okay, now you’re playing tricks on me,” Rus said flatly. “i’ve never even heard of such a fucking thing!”

“Well, we haven’t had to worry about it since the time period just after the war,” Undyne told him with a little shrug, “To be honest, we’re bordering on overcrowded. It’s only when the populace starts dipping dangerously low that it can happen.” 

“so, what this is saying,” Rus tapped the yellowed pages with a fingertip, “is monsters might go into heat if they have a low population.” Like, say, Monsters getting dusted every day and twice on Sundays, in another universe where murder was less a terrible offense and more of an easy solution to a variety of problems.

“Yes,” she nodded eagerly. “M-most of the literature is, hm, from right after the war. There was a wave of heats going through all Monster’s species when our population was close to extinction levels. Of course, that was a long time ago and we haven’t seen anything like that since, but the Royal Scientist back then kept meticulous records.” 

“yeah?” Rus asked, absently, still flipping through the journal. The handwriting was strange, antiquated, which he supposed made sense since this was probably written before the Queen had shed her first winter coat, “who was it?”

“Um…I’m not…” her eyes went vague and she shook her head. “Anyway, see here?” the page was full of grainy sketches, the faces discreetly blurred but all of them showing a small wound of some sort on their necks. “Monsters in heat stabilize quickly with a mate. They usually mark their mate, somehow. The most common method was biting, but a species without teeth might scratch a mark or even use some kind of ink or paint to draw it.”

Oh, fuck.

Rus swallowed dryly and kept his hands on the pages, didn’t reach up to touch the aching bitemark hidden beneath the collar of his sweatshirt. It was throbbing anxiously along with the pulse of his soul. "what…” his voice cracked, and Rus cleared his throat, “what if they mark someone who isn’t their mate?"

She blinked, her eyes owlishly large through her glasses. “I—I don't remember anything like that in the literature. It’s hormonally driven, I wouldn’t think they’d want to mark anyone other than a potential mate and anyone compatible would probably already be in heat themselves. Even if they weren’t, no monster who wasn't interested would chance getting close enough for it to be an issue. I-its fairly obvious, if you know what to look for. Like you were saying, sweating, aggressiveness—"

“a weird smell,” Rus muttered. 

That got him a strange look. “Um, maybe? There’s a notation on a release of pheromones, that could have an odor…d-did you find another book about this, is that why you’re asking?”

“something like that,” Rus managed to give her a toothy grin even though he’d never felt less like laughing in his entire fucking life. She still seemed a little too interested, even suspicious, and Rus added hastily, “thought it might make an interesting idea for a story…maybe a manga.”

That did it. Her eyes went a little starry. “R-really? Are you going to p-post it on the Undernet?”

“might, when it’s done. okay, so, monsters go into heat and what, they get a little busy and they’re done? can’t they, you know?” He offered her a few hand gestures to convey a variety of self-service options and her cheeks flushed dark purple. But damn if he didn’t know his audience, because she giggled, too, covering her eyes.

“No, no, it’s not the kind of situation where you can help yourself. That’s why Monsters need a mate for it. Heats are usually only a problem if they don't.”

There was the info he was looking for, “so what if they don't?” 

Her expression turned serious, her blush fading. “It can be dangerous, to themselves and to others. Monster in heat have been known to die from it, or to kill other Monsters in search of their mate. Not their fault, of course,” she added hastily, “can’t battle evolution. They really fixate in their mate,” she sighed. “A shame it doesn’t happen anymore, it’s sort of romantic!”

“romantic,” he echoed hollowly. Yeah, it was an real assload of flowers and kisses, wasn’t it.

“W-was that what you needed to know?” she asked hopefully. “C-can you use that for your manga?” 

“it was just about perfect, ‘dyne,” he said honestly, “exactly what i needed to know. tell you what, i’ll let you read my manga when it’s done, sound good?”

Which would be never, but it wasn’t actually a lie. He owned her big time for this, though, he’d have to think of something to make it up to her. With a flourish, he sat the Mew Mew Kissy Cutie manga on top of the journal and handed both to Undyne, who was already flushing again, looking at the manga almost hungrily. 

“hey one last thing, undyne,” Rus gave her a gentle poke, startling her from her manga hypnosis, “you think the symptoms of heat are pretty obvious, right? if you know what to look for?”

“Probably not to anyone today,” Undyne gave him a nervous smile, “Or you wouldn’t be here asking about it, but I would think it was back then. The symptoms are pretty distinct.”

“yeah,” he said softly, “that’s what i thought. thanks for the help, sweetheart.” He hesitated at the door, but Undyne hadn’t opened the manga yet, and he decided to risk it, “tell you what, when you finally decided to write that letter you talked about on the undernet? i’ll deliver it for you, if you want.”

Her cheeks went bright mulberry. “Papyrus!” she moaned, covering her eyes. “I-I couldn’t…she’d never---”

“won’t know unless you try,” Rus shrugged. “anyway, i got some things to take care of, i can find my own way out. maybe i’ll see you soon, okay?”

“After working on that manga, I hope,” she teased, and yeah, he’d have to stop by again. Undyne was a good egg, she didn’t deserve to be here alone all the time, but that was for later. 

Rus exhaled slowly, thinking of the problem at hand. Or rather, at other body parts. “yeah, i’m betting i’ll be getting started on that project real soon.”

tbc


	3. Chapter 3

**Summary for the Chapter:**

> Rus has his answers, there’s just one more person he needs to talk to and he’s a hell of an asshole. This surprises no one.

* * *

Underfell was fucking dangerous but Rus knew his way to Red’s sentry station in Snowdin. It was a mirror-version of his own world, a left turn instead of a right, and while miscalculating a shortcut could have consequences, he wasn’t worried about that right now. At least ending up halfway in a tree would solve a few problems. 

That said, he didn’t want to step out into the middle of some kind of territorial dispute or road rage, or whatever the fuck it was that made the denizens of Underfell so damn dust-thirsty. His shortcut left him in a nearby copse of trees, looking out from around one of them warily. 

There was nothing in sight but more snow and trees, and the sentry station itself. In other words safe-ish, a relative term in Underfell. 

The sentry station was even more haphazard than the one in Underswap, made from moldering boards, snow dripping from every eve. And Red was slouched in a rickety chair, eyes closed, with his feet propped up and a slender cigar smoldering between his fingers. 

Snow crunched beneath his sneakers as Rus walked over, his feet sinking into the drifts until he got to the road. It was almost insulting that Red didn’t even open his eye, only took a slow puff from the cigar. “you look like a fucking target in that sweatshirt, honey bun. shoulda taken a cue from paps and doctored it up with a little sharpie ‘cause you may as well write yourself up an advertisement for free xp.”

Rus ignored that, the implied insult. He wasn’t a fighter and he knew it, had never wanted to be a guard or a warrior, had never needed to be. He was who he was, and that wasn’t something this asshole could simply abuse. 

“you son of a bitch,” Rus ground out. His magic was running hot, untouched by the chilly air, his vision shading into searing orange.

“what?” Red finally looked at him, his sockets slitting open to reveal lazy crimson eye lights. He couldn’t quite manage innocence, Rus had never expected _that_ of him, but he’d let himself be fooled by appearances once. He’d known who Red was, how the denizens of Underfell were, and yeah, Red resembled his brother, but he wasn’t like Blue he was like…

_(me)_

…an asshole. He really should have known it was Edge who mirrored Blue, the same as Papyrus. The protector, the guardian with an impeachable code of honor. He was clear of the blinders now and what Rus was getting from Red was that he had fucked both him and his own brother over. Literally.

“do not try that shit with me,” Rus snarled. It still hurt, to think someone with his brother’s face had used him like this. “you knew! there’s no fucking way you didn’t!”

“figured it out did ya.” Red stuck his cigar between his teeth and gestured imperiously for Rus to lean in. Reluctantly, he did and Red tugged down his collar. He winced as Red prodded the bite mark roughly. "got you good, didn’t he.”

Rus shook him away, standing up straight and demanded, “why me?”

It gained him a lazy shrug, Red taking a long draw off his cigar and his words came with a stream of smoke. “there’s no one else, really. can’t trust anyone in underfell, they’d use it against him before the come was even dry. can’t exactly help him myself, even if i wanted to. heats won't mark too close a relative. they smell like dirty fucking socks or spoiled meat, it’s kinda a turn off.”

He tapped ash into the snow, scattering gray, “sans and papyrus, they seem to be too close, they don't work. something about you and the blueberry, though. whatever jumble your universe has going for it, you're different enough to twig to it. noticed it during my last heat.” Red grinned slowly. “bet you remember it.”

He did, Rus realized. At movie night a few months back, Sans and Papyrus had both been complaining about a rank smell all night and had finally left early. Rus had figured that the damn dog had hidden something that was rotting merrily away somewhere in the house, but he and Blue had never found it, hadn’t even been able to smell it. They’d been puzzled by Sans and Papyrus’s complaint and by the next movie night, it had been gone.

“yeah, you remember,” Red said softly. “that’s when i figured out your ‘verses don’t get ‘em. and that was just the pre-show, you weren’t even catching the sweet side yet, the stink comes early so family has time to clear out. gotta tell ya, this is his first heat, they’re always the worst. he was gonna tough it out, but i’ve seen how that can end.” He shook his head, “i can’t risk it, not my bro. so it had to be you.”

Rus really wished he could shove away that niggling feeling of calculated understanding. What would he have done if it had been his brother, what wouldn’t he do…still. “you could have asked!”

“coulda,” Red agreed amicably, “but i didn’t have many ideas if you said no, and then you would have had advance warning. nah, my way worked fine,” His grin turned sly, his sockets half-closed as he tipped a look at Rus. “you should be thankin’ me. figured you were experienced enough to handle it. i coulda picked your brother.”

Any faint sympathy in his soul went cold and the sharp heat of his anger turned to icy fury, "you fucking—"

He didn’t even think, reaching out with blue magic and flinging Red out of his chair into the snow. For a moment, Red blinked up at the sky, wheezing, before he rolled over onto his hands and knees. Slowly, he climbed to his feet, dusting snow off his jacket. His grin bordered on feral, sharp and glistening. “you get that one for free.”

“don’t you even talk about my brother!” Rus shouted, past caring if anyone heard and came to investigate. He sent a wave of jagged bones at Red, watching furiously as he lazily sidestepped it, and impending danger didn’t register until he saw the flare of crimson in Red’s eye socket. 

By then it was too late, snow was cold beneath him and he couldn’t breathe, couldn’t _breathe_ , strangling on blue magic that wasn’t merely pinning him down, it was holding him completely, to the point he couldn’t even suck in air. Panicked, Rus struggled, uselessly, his vision blurring, darkening, until it let up enough for him to gasp, gagging on magic. He was still pinned down, but he could breathe again. Some cold, efficient part of Rus noted that it was a remarkably effective attack; couldn’t summon your own magic if you were focused on suffocating. 

That infuriating little bastard strolled over to stand next to Rus, his hands in his pockets. Aside from the sharp glow in his left socket there wasn’t even a hint of strain. His grin was cold, calculating, and Rus swallowed down a touch of real fear. 

“said you got one freebie, didn’t I, you don’t get to double dip. i could take you back there right now, you know,” Red said idly, nudging at him with the toe of his shoe. “tie you up pretty as a present. i’m betting my bro doesn’t have a whole lot of ‘no’ left in him.”

The pressure tightened again, until Rus strangled out a cry, then it let up entirely, allowed him to roll gasping to his side. “don’t think i need to though. you and i are a lot alike and—"

“we are nothing alike!” Rus spat, struggling to his feet. His clothes were soaked through from snow that had melted beneath him from the heat of their magic, sagging heavily on his bones and his ribs ached from being compressed. 

Red only picked up his cigar, grimacing as it drooped soggily. He tossed it aside, muttered irritably, then snapped at Rus, “yeah, you can spout that party line all you want but we both know better. i _know_ you, a little of me _is_ you, you shit, and i know there’s nothing you wouldn’t do for your bro. and i can’t help but think there’s a few things you might be willing to do for mine.”

“you…you…” The cold was creeping in now, fucking hell, and Rus couldn’t tell if it was the chill or his own fury making him stammer. 

“besides, you can quit pretending like you’re some kind of screaming fucking virgin anytime now,” Red grinned, but his eye lights were pitiless. He slouched back into his chair, propping his boots back up. “i hear things, even in your ‘verse. you’ve flapped your knees for half of underswap, what’s one more?”

It made him wince and Rus glared at Red furiously, “that was my choice, it doesn’t mean you can set me up as a whore for your brother! if you have a problem with me fucking around, you can stuff it up your sanctimonious cockhole, you psychotic piece of shit bastard.”

“’course it was your choice,” Red said agreeably, “and so is this.” He rolled back to his feet, stalking over and poked Rus in the sternum, his sharp fingertip digging through the thick material of his sweatshirt. “you’re right, that what you wanna hear? i set you up and you can go ahead and be pissed at me. you can hate me all you fucking want. i deserve it. the real question is, are you gonna let my bro die because of it?"

Rus looked away.

“you—” he stopped, grinding his teeth. There wasn’t an insult he could think of that would convey the purity of his anger right now. He doubted he needed one, Red knew exactly what he was thinking, all of it was visible in his smirk. He turned on heel and marched away and moments before he shortcutted away, he heard Red call out, his gravelly voice sweetly cheerful.

“have fun, honey!”

He stepped out of the shortcut into the machine room, the worse place to be with the way he felt. He wanted to break something, feel it shatter, he wanted to scream. 

“I’m going to kill him,” Rus ground out, knew it for the lie it was before it ever left his mouth. He wasn’t, he couldn’t. Even if he had a chance to beat Red in a fight, he couldn’t hurt anyone who looked so much like his little brother. He laughed, then, sinking down to the floor, muffling it with his hands, and hating the hysterical edge to it, but he couldn’t stop. 

“looks like i’m fucked,” he giggled, laughing until he felt tears sliding down his cheek bones. He wiped them away roughly and shook himself. 

Enough self-pity bullshit. Red was right about one thing, at least; this wasn’t Edge’s fault, and if Red had bothered to ask, if he’d actually sat down and told Rus what was going on, he probably would’ve said yes, anyway. Oh, he’d have blustered and fussed about it, he knew himself well enough for that. But…yeah. It wasn’t in him to let anyone suffer, not even Edge. Undyne had said he was going to hurt himself or someone else, and Rus was guessing it would be soon.

“it’s your choice,” he muttered to himself, fingering the mark on his collarbone. It itched, dry marrow flaking beneath his fingertips. “your choice, so fucking make it.” He nodded a little and made his way over to the machine.

If they were going to do this, he had a few things to take care of first.

 

tbc


	4. Chapter 4

**Summary for the Chapter:**

> For better or worse, choices have been made. Time to reap the consequences.

**Notes for the Chapter:**

> Here we go...

* * *

It was like déjà vu to teleport into the Fell brothers' house, this time with a bag over his shoulder. This was all pure guesswork on his part, but it didn't take a PhD to figure that some lube, a few bottles of water, and a change of clothes was probably a good idea. 

Nothing had changed, the living room was still a clutter of dirty dishes and laundry. But the smell was so much stronger, almost enough to make him stagger, eye-wateringly ripe, only now it smelled fucking delicious. Rus took a long breath and slowly pulled his sweatshirt off, hanging it over the back of a chair. There was no telling how this was going to turn out and he was pretty fond of this one. He slipped off his shoes and that left him in a tank top and track pants, easy clothes to navigate.

All that was left was psyching himself up.

The truth was, he hadn’t had sex in a couple of months. He wasn’t naïve about his issues, thanks, he was more than aware that he used sex as something of a pressure valve, losing himself for a little while in an anonymous body, but lately, spending time with their alternates had been easing some of that. Suddenly, there were other skeletons, ones who _understood_ , and while a couple of Monsters had been disappointed that the pussy store had closed shop, most of them had been agreeable about it. No one had made any promises to anyone, it had been a mutual benefit that had dried up and Rus’d been okay with going solo for a while. Or he had, until Red decided to have his brother plug into him like quarters in a slot machine.

No point in thinking that way right now. This was like any other time he’d had a one-nighter, that was all this was going to be. A little necessary relief and from his growing reaction to that smell, the lube probably wasn’t going to be necessary.

He went upstairs a little quieter this time, cautiously. The bedroom was still dark as the void, but Rus was ready for it, switching on a small battery powered lantern. Electricity was finicky in Underfell and he’d be damned if he was doing this in the dark.

Without the distraction of thinking Edge was dying, Rus was able to get a better look at the room. No race car bed here, only a utilitarian headboard and mattress. There was a bookshelf in a corner crammed with tattered volumes. The sight gave him a pang of guilt even through the blearing rise of desire. They had plenty of books, and Blue would be happy to loan them, but of course the Edgelord wouldn’t ask. Another task to assign to his little brother. Operation ‘Use The Library, Asshole’ to go along with the leftovers. 

Enough poking around, (heh), time for the main course. He was as ready as he was ever going to be. Edge was curled up in the middle of the mattress beneath a blanket, looking sweaty and miserable. He was twitching, little helpless jerks, and his face was tight and pained. It made an honest pang of sympathy flash through him, come on, hadn’t life already dealt the residence of Underfell a bad hand and now there was this cherry added on top of a shit sundae.

Rus set his bag by the side of the bed. The clunk it made was soft, but Edge lurched up, a half-formed attack already in his hand. His eye lights were unevenly lit, disturbingly wide and Rus wondered how well he could even see. Well enough to scramble away when he realized who was there and Rus could only watch, torn between frustration and sympathy. Somehow that was worse, to see Edge fleeing from _him_.

Reddish sweat was dripping from Edge’s bones and that heavy, musty smell was overpowering, enticing. Rus already felt a little hazy, his own magic damp and soft between his legs. 

Edge was still looking at him almost fearfully and Rus held out his empty hands, keeping carefully still. "it’s okay, kid."

“Don’t call me that!” Edge hissed. Even in the dim yellow light of the electric lamp, there were darkened shadows visible beneath his sockets, his magic shining hotly in his joints; he looked like he’d gone through hell in the few hours Rus had been gone. From the way Undyne and Red had described it, maybe he had. 

His own magic was warming, too, reluctant anticipation combined with that mouthwateringly intense aroma. "sorry, habit. you're the same age as my bro.”

"And he isn’t a child either!"

"nope, but until you're older than me, i reserve the right to call you kid,” Rus took a careful step closer and Edge flinched back, cringing into the wall. “look, i know what's wrong, i'm here to help."

Edge's eye lights were burning coals of red and they didn’t seem able to be still, drifting over Rus only to jerk back up to meet his own. "Get the fuck out."

"ain't gonna happen, may as well give in gracefully." Hopefully more gracefully than he had, Rus thought ruefully. He took another step closer. 

There was nowhere for Edge to escape, he was tucked into a corner. He was shaking, tremors wracking him, "I won't...get...get out…"

“it’s okay,” Rus soothed, reaching out but not touching, not yet. Edge shook his head wildly, droplets of sweat flying. 

Red had been wrong, Edge had a little no left in him. What kind of flipside shittwist was this that Rus was trying to seduce the one in heat? How did he get stuck with the one asshole so uptight he couldn’t let go even when biology demanded it? Okay, time to turn this up, they didn’t have all fucking day. 

"besides, you already marked me, didn't ya?" Rus pulled the front of his tank top to the side, the strap falling off his shoulder, and Edge's eye lights followed it, staring at the clotted bite mark. Rus stroked a thumb over it, deliberately, and a low sound rose in Edge’s throat. "i'm here and i'm offering, you hear me? i’m saying yes. it's okay, sweetheart, i promise."

“don’t call me that, either,” Edge whimpered, fucking _whimpered_ , and he curled up a little into himself, but he never looked away from that mark. 

“pick a pet name and i’ll run with it,” Rus told him. He put a knee on the mattress, breathed in that sharp, ripe smell and leaned in to let Edge get a good look at him, at the bite. “anyway, as it’s been pointed out to me, i’ve already fucked my way thru half of underswap. if you’ve had a hundred dicks, may as well go for a hundred and one."

There was no time to react as a hand flashed out and grabbed his shirt, yanking him into the bed. Rus followed it, staggering, let Edge push him into the sweat-stained blankets. In an instant, Edge was looming over him, settling between his legs, and hot jealousy was visible in his eye lights.

Ah. Well, that was one way of getting it done. Rus winced as he heard tearing fabric, doubly grateful he'd stripped off his sweatshirt downstairs. It was one of his favorites. He kept himself relaxed as Edge scrabbled at his pants, lifting his hips as he tugged them down. His cunt was already formed, the magic glowing softly in the darkened room, and the insides of his femurs were already stained with wetness. 

It left him in nothing but the shredded remains of his tank top, Edge already mostly bare against him, his bones achingly hot to the touch as Rus caught hold of his shoulders. He braced himself on his arms over Rus, glaring down at him. Almost, Rus expected another round of protests, a few ‘get the fuck out’s’ thrown in for good measure. He startled when Edge ducked his head instead to fit his teeth against the mark on his collarbone. Rus braced himself for pain but there was nothing, only frantic gusts of breath against him, his tongue pressing hotly against it and a groan muffled into bone.

Even a virgin would have understood the implications of the hard, hot length pressed firmly against his pelvis and Rus hadn’t been able to claim that title in years. 

“c'mon," Rus whispered. He lifted his hips, rubbing deliberately against him, encouragingly, "you don't have to wait anymore. i can take it, come on."

"I'll hurt you." It was a groan, a plea, revealing the barest thread of control and all Rus wanted was for it to fucking _break_. 

"By fucking me?" he scoffed. He shifted, worming a hand down between his legs and pressed two fingers inside his cunt. The sound of it was wet and obscene. He'd stopped by home and done a little prep work when he'd gotten supplies, made sure he was worked up, and with those pheromones doing their job, he was more than ready for this. 

"hear that?" He pulled his fingers out with a deliberate slick sound, wagging the orange-tinted digits in front of Edge's sockets. "i'm wet for you, i'm ready, come on!"

He had to bite back a yelp as Edge caught him by the wrist, yanking his hand up and sucking on those wet fingers. His tongue wrapped around them, wriggling against his knuckles, lapping it up. Edge was groaning, and he could feel the vibration of it, all fucking hell. 

"edge, c'mon," Rus moaned. He spread his legs wide, lifting his hips, his cunt felt achingly empty, he was ready, damn it, more than ready, he needed this, he needed Edge inside him and he needed it now. 

Edge still had him by the wrist, forcing it back against the bed and any thought of protest fled when Rus felt the tip of his cock press against him, slicking through his folds. He tried to encourage him, wrapped a leg around his hips and tried to pull him in.

"yeah, that's it, baby, that's it,” Rus murmured, “come on, push in, get in me deep, make me feel it, make me _taste_ it."

"Shut up," Edge growled and Rus had to laugh.

"yeah, good luck with that...fu--uck!!"

His voice broke as Edge shoved in hard, left him choking on his words because fuck, Edge was not a small boy, not even a (heh) little. He was still going slower than Rus would have expected, trying to be gentle, but fuck that. He hadn’t died from fucking yet and now seemed like an excellent opportunity to put that to the test. He wrapped both legs around Edge’s hips and arched up, dragging him in hard despite Edge’s startled yelp. Until he could feel the scrape of his pelvis against his public symphysis and Rus could only blink up at the wavering shadows on the ceiling, gasping as he strained for more. 

"oh, that's deep, that's so fucking deep, oh, baby, yeah, that's it, come on, fuck me deeper—"

He wasn’t moving, all fucking hells. Edge was breathing heavily, his shoulders heaving, and his cock was so deep inside him, stretching him, spitting him on the length, but he wasn’t _moving_ , only staring down at Rus with those too-wide eye lights. Nothing but unsatisfying little shifts of his hips, tiny unconscious movements. Rus tried to twist his wrist free, could feel bruises rising from Edge's grip. By all the little angels, he couldn't remember ever wanted to get fucked so badly, to feel a hot, hard cock driving into him, how was it Edge had enough control left to keep still? 

He gave Edge a glittery, heated look, running his tongue over his teeth. "still think you’re gonna hurt me?" 

"I won’t.” Ragged and lost as it was, it sounded like a promise.

But not one that Rus particularly needed. The burn of desire was growing painful, "S'ok, you can hurt me a little, i don't mind...ah! oh, stars, oh, _fuck_ , edge!"

The first real thrust took him off guard, Edge pulling out until only the tip was left inside him and then driving back in, a long, inexorable movement that sent sparks flying up his spine. It hit him too fast, too much, and frantically, Rus reached between them and thumbed his clit, coming hard, arching up and low cries choking out of him. Fuck, he’d never come that quickly before and when he came back, he blinked up dazedly to find Edge watching, his eye lights hot. 

“your turn,” Rus rasped out and Edge nodded slightly, his hips rocking, and now they were getting somewhere. His rhythm was a little stilted, uncertain, nowhere near the wild, uncontrolled fucking that Rus had been expecting, but it seemed to be doing something for him. It was doing plenty for Rus, the girth of his cock was a delectable stretch and it didn’t take much wriggling to get a good angle. Rus lifted into each thrust the best he could, murmuring encouragements and running his hands over sweat-slick bones, teasing at sensitive cartilage and drawing out shivers and groans. Maybe neither of them had really wanted to go here, particularly with each other, but it might as well be good. 

All that tight control, that care, was unraveling and those thrusts were getting harder, almost rough. One hand stayed on his wrist and the other was clutching his pelvis, sharp fingertips digging in with a hint of tantalizing threat. His thrusts were bordering on manic, and here it was, the wildness he’d been expecting, the desperation. Edge being so out of control was so wrong, but it was also fucking hot, and he was gasping, straining, chasing his need.

Rus felt it the moment he caught it, he could _feel_ Edge's cock swelling inside him, that was something new, not painfully, but it stretched his walls, ratcheting him up to his limit before Edge choked, his breath hissing out through his teeth as a gush of hot come filled him. The feeling was enough to set Rus off, groaning as he came again.

He was still shaking with it, panting and trembling when Edge yanked himself free, fast enough to make him wince. “easy there, champ—" he began.

Only for his words to cut off with a startled whuff as he was flipped over on his front and dragged up to his knees, and before he could so much as yelp in surprised, Edge was inside him again, thrusting vigorously, the rough slide of his shaft filling him from a new angle, somehow even deeper.

Rus scrambled to brace himself before he faceplanted into the mattress, groaning out, “fuck!”

Immediately, Edge stilled, shaking hard enough to rattle against Rus, his hands painfully tight at Rus’s pelvis, keeping him from moving, “Are you all right?”

“don’t stop!” Rus snapped. He fought against that grip, trying to force Edge into him again but he was too strong, and he could only writhe in helpless frustration. “fuck me! come on!”

It was enough. Rus braced himself as best he could, hanging on as Edge let the hunger overwhelm him again, following his need and that was perfect, that was what Rus wanted, what he needed, this glorious fucking. 

Rus lost count of how many times he came; his thoughts were hazed by either the cloud of pheromones or his constant state of near orgasm. It seemed like Edge’s cock never left him. He’d be on his knees then suddenly pulled up to sit astride his lap, only to find himself on his back, his legs drawn up over Edge’s shoulders. There was no reality past the delicious pleasure in his swimming consciousness, the hot flood of come filling him again and again, and he couldn’t say where his moans began and Edge’s ended. 

By the end, his head was starting to clear, exhaustion finally overtaking desire. All but collapsed on his back, with his legs sprawled apart and above him, Edge couldn’t even hold himself up, all his weight pushing Rus into the bed as his hips moved weakly. 

There were tears rimming his sockets, his expression startlingly vulnerable as Edge struggled over him, still trying to thrust, achingly hard and moving in the growing soreness of Rus’s cunt.

"I can't…" Edge gasped wetly. Every sound he made was closer to a whimper, his bones felt hot, overstimulated.

"yeah, you can," Rus crooned, tenderness welling up in him. Tired as he was, he hitched up into Edge's weak movements encouragingly. "i've got you. one more time, yeah? one more time for realsies, i promise, you can do it, come inside me, i'm drenched with your come, get me wetter, get your come in me. "

It was enough. There was hardly more than a tremor to mark it, but wet as he was, he felt that bare spurt of come inside him. Rus petted his skull as Edge sagged down on him. Too heavy, but for the moment at least his weight was comforting. “there you go, love, you did it, you did real good.” 

Pointless. Edge’s breathing was evening out, Rus’s prediction that this would be the last time coming gratefully true. Before he could drop off entirely, Rus managed to push him off, at least enough so that he could damn well breathe. Not enough to get Edge to let him go, but that was all right. A couple of possessive hands were easier to manage than the entire weight of another Monster. 

Now that thinking was becoming possible again, Rus took a second to regroup. From the sticky, damp feeling of the sheets he was thinking it would probably be easier to burn the damn things than to wash them, but at least they’d contained the damage to the bed. Besides, it wasn’t like Rus was going to be doing any cleaning aside from himself because he sure as fuck wasn’t shortcutting anywhere without a shower. 

He sincerely doubted anyone was going to give him a medal for this, but he deserved at least a first shot at the hot water. He felt like he had come in every crevice and joint, and when he was less tired, it was going to be pretty disgusting. 

Edge shifted a little against him, settling his skull on Rus’s ribcage. He looked as exhausted as Rus felt, especially with the hours he’d spent in heat beforehand tacked on. Sleep made him look younger than his normal scowl allowed, and reluctant tenderness rose in Rus again. Edge had more than enough years on him to be considered an adult, but he wasn’t exactly a grizzled old elder either. If this was his first time, he’d just gotten one hell of an introduction.

With the tips of his fingers, Rus managed to snag the strap of the bag he’d brought, fishing out a bottle of water and downing it greedily. That helped right there. He’d pour one down the Edgelord when he woke up. He couldn’t help giving the bag a longing look, though, he’d dust someone’s mother for a cigarette right now. Maybe Edge wouldn’t notice--

Rus grimaced. No. He wasn’t up for much if he accidentally woke Edge up and he decided it was time for round fifty, or wherever the fuck they’d ended. He kept hold of a bottle of water, though. If Red peeked in on them, he was going to nail the little fucker right between the eyes.

Edge was still clinging to him like an oversized skeletal teddy bear and that was fine, he hadn’t been planning on leaving yet, anyway. The last thing he wanted was to go through all this only to have Edge dust because Rus hadn't waited long enough for his pheromones to settle or for him to give him another love bite or whatever else was supposed to happen. Probably should have flipped to the ending of Undyne’s book and checked for spoilers, little late to worry about that now. 

At least the major perk of having sexy bits that were magic was once they were gone, you didn’t have to feel them anymore. He was still sore as all fuck, felt like his hips were unstrung, but the dull ache in his cunt was gone with nothing more than a little concentration.

The blanket hadn’t escaped the carnage, as damp as the sheets. Rus managed to hook a finger in the corner and flip it over them anyway, since it was starting to look like Edge wasn't letting go. Eh, that was all right. He'd stay a little while, just to make sure he was okay. Hopefully he wouldn’t be too shouty when he woke up. It hadn’t gone bad, as far as Rus was concerned; no one had dusted, free orgasms all the way around, and once Rus’d had a couple of days to stop walking like a drunken pirate, they could both toss this particular event into a mental suitcase and bury it beneath a fucking tree, never to be discussed again. 

It had worked out and Rus was going to count his fucking blessings. Someone needed to and somehow, he doubted Edge was going to be writing him an effusive thank you note.

More’s the pity. 

tbc


	5. Chapter 5

**Summary for the Chapter:**

> It's the morning after and everything is swell.

* * *

When Rus opened his sockets, the first thing he saw was what passed for weak morning light streaming in through the barred window. It took a minute for him to grasp what that meant, blearily trying to understand how his window had grown bars overnight and why was his bed in the wrong place, or more to the point, in the wrong room, and why the fuck did all his bones _ache_ like he’d taken a jog from Snowdin to New Home in his sleep and why was there a warm presence in the bed behind him—

Oh. Right.

Wasn’t much he could do but roll over, steeling himself for what he was gonna find.

Edge was awake, his skull resting on the stained pillow, staring at him. Huh, Rus hadn’t realized that eye lights could burn like that, a bright hazy swirl of anger, and the crimson color made them look like a pair of miniature suns, glaring at him in silent rage.

Welp, this day was starting swell. Par for the course the way this week had been going. Digging through the tangle of blankets, Rus found the bottle of water. It was warm from being in the bed with them, but he offered it to Edge anyway. “here.”

Whatever his temper, it didn’t stop Edge from cracking it open and gulping it down. The way he simply tossed the empty bottle in the direction of the floor made Rus wince. The Edgelord, in such a mood he was willingly making a mess? Yeah, this was going to be fun. 

He seemed to be struggling with finding something to say, a low, frustrated sound coming from his throat until he finally managed to whisper, “How dare you?”

“yeah, sorry about keeping you alive,” Rus snorted. Wasn’t like he was expecting flowers and a thank you letter but damn, a little appreciation would be nice. For the briefest of seconds, Edge’s eye lights flared, bright as coals. Then that anger seemed to collapse, whuffing out, his eye lights fading to normal. 

He closed his sockets wearily, dropping his head back onto the pillow. “You have no idea what you’ve done.”

“uh, yeah, i saved your ass,” Rus said irritably. He might not have a PhD in this shit, but it wasn’t like there was a host of other options once Edge had given him his little heat nibble. What was done was done, what was the point of being pissed about it?

Then again, Edge had always excelled at a constant state of simmering anger and Rus wasn’t surprised at all when he snarled out, "I didn't ask you! I _told_ you to leave!"

"yeah, well, someone did the asking for you," Rus grumbled. Let Edge figure out for himself what his brother had done.

"Get the fuck out,” Edge ordered. He shifted away from Rus, rolling so that he was facing the wall. Even Rus understood the implications of a Fell monster showing their back to the enemy, what a fucking _prick_. 

"gladly, asshole," Rus muttered. All the little fucking hells, he needed a cigarette. 

And a shower, he felt disgusting, dried come flaking off his bones along with the stickiness of sleep-sweat. He needed plenty of hot water and maybe an old toothbrush to scrub all the nooks and crannies, and a chance to sleep for about three days. And a complete absence of Fell Monsters in his life for, oh, maybe forever would be good. 

Not that he was gonna get that, not with movie night in a few days, but pleading ill was starting to sound like an excellent plan, at least for this week. 

It was a struggle to get out of the bed and Rus couldn't completely stifle a low sound of pain. His legs felt like they were made of spaghetti, Papyrus’s special recipe that managed somehow to be overcooked and yet a little crunchy at the same time. The ache in his pelvis protested any movement strongly but it was going to have to deal until he got on enough clothes to feel comfortable taking a shortcut. He’d never seen any creatures in the void but if there were any hanging around, he wasn’t interested in giving them a front row seat in a showing of his bare ass. 

He was struggling to pull the spare pants he’d brought out of the bag when Edge spoke again, startling him. 

"Wait."

Warily, Rus looked back to see Edge had rolled back over, sitting up so that the blankets had fallen to tangle around his pelvis. He didn’t seem too concerned about his nudity, but Rus felt a little warmth heat in his cheekbones at his own. Stupid, he’d spent half the night fucking this guy, once you had someone’s come drying on your femurs, it was a little late to play shy. 

"what the hell do you want now?" Rus sighed, tiredly. All he wanted was to go home and start forgetting about all of this. That, he could do, Rus was an expert at Not Thinking About Shit and this event was about to soar to the top of his list. 

"Did I hurt you?" Edge was looking him over intently and Rus blinked at that unexpected non-sequitur. Oh, for fuck’s sake, now he got to have a someone else’s guilt for breakfast? No, thanks. 

“i’ll be fine,” Rus said shortly. Then promptly groaned as he struggled to pull his pants up his legs, damn it. 

“Did I _hurt_ you?” Edge snapped and Rus gave up. Fuck all of this, fuck Edge’s ingratitude, fuck Red for getting him into this, fuck the biology that had caused it and fuck Underfell for sucking so much that it was necessary. Fuck everything.

"you spent half the night fucking me, what do you think?" Rus retorted. Edge flinched; he looked miserably unhappy, and Rus sighed. How was he the bad guy here, exactly? "i'm fine, okay? nothing that a shower and some actual sleep won't cure."

"Let me help you."

Dumfounded, Rus stared at him. "what?"

Edge blew out an impatient breath. At least the last of his anger seemed to have drained away. "You can barely stand, let me help you."

Discomfited, Rus rubbed the back of his skull and considered that. For all that he’d seemed pretty damn ungrateful when they’d woken up, Rus did have a little of Edge’s number. Probably felt like he owed Rus _something_ , yeah, someone from Underfell surely saw it that way. Rus didn't much want favors for plenty of reasons, particularly since, his rotten temper aside, none of this had really been Edge’s fault, but…what could it hurt? Irritating as Edge was, Rus couldn’t really say he’d have been in a good mood waking up if their positions were reversed.

He should just go home, he really should, but—

"all right," Rus agreed, warily. 

Going from trying to wince his way out of bed to being scooped up into strong arms was a bit of a shock and Rus yelped, clinging frantically. Edge was surprisingly gentle, though, carrying him out into the hallway to the bathroom. He sat Rus gingerly on the commode and turned to the shower, fiddling with the controls until steamy water poured out, fogging the mirrors. 

It was still pretty damn weird to be naked in front of Edge, even filthy as he was, and Rus pushed down his embarrassment determinedly as Edge helped him back to his feet, guiding him to the shower stall. "Is it warm enough?"

Hesitantly, Rus reached in and let the hot water pour over his hand. It was right around temperature of a lava flow in Hotland, so perfect. "um, sure."

Edge helped him into the shower and for a moment, Rus doubted his wobbly legs were going to hold him. He didn’t have to worry long, Edge stepped right in behind him, his hands catching on the outer crest of his pelvis, steadying him. 

"okay, this is different," Rus muttered but he didn't protest. The heat was gorgeous, already easing some of his aches, and Rus would have been happy to stand in that steamy spray for about a year. 

Distantly, he felt Edge’s grip lighten, then release him when it became apparent that he wasn’t going to collapse into a pile of loose bones in the tub. He figured Edge was going to leave him to finish, or maybe shove him out of the way to get in a good rinse for himself, so when a soapy washcloth started scrubbing his bones, he couldn't help a startled groan, "fuck, that feels good."

It started at his skull, already mostly clean from the water pressure. The strong, soapy-clean smell was soothing in its own way, and Rus braced his hands against the shower wall, holding still as the cloth worked its way lower. Along his humerus, down his radius and ulna, going as far as his wrists before withdrawing. A pause, and he heard slick movements, Edge re-soaping the cloth before it returned. Every rib was given careful attention, from front to back and then the length of his spinal column, with such thoroughness that Rus was close to melting, his aches and pains drawn loose, leaving him relaxed and sleepy. 

He tensed as it slid lower still to his pelvis, moving very gently against his pubic symphysis, which was wincingly sore. He couldn’t deny that he needed a good bit of scrubbing, though, and Edge was careful, working the cloth cautiously against his sacrum and coccyx. Exhausted as he still was, the feeling of cloth-covered fingers on sensitive bone was unintentionally stimulating, and Rus could feel his cheekbones heating to match the temperature of the water as his magic condensed between his legs, happily responding to that soft touch.

"sorry," he muttered.

"Don't be ridiculous," Edge said. His voice cut through the low roar of the shower, curt but not unkind. He soaped his way lower, down Rus’s femurs, his tibia and fibula, cleaning Rus to his toes before journeying back up. Slower now, hesitating on his femurs, still sliding lightly against him, and Rus held his breath.

This…this had stopped being only about getting clean far too long ago. The thick cloud of magic in his pelvis coalesced into his cunt and Rus could feel a heavy rill of slickness trailing down the insides of his femurs. He looked down, narrowing his sockets, watching as that trickle of orange met with the washcloth and soaked it, thinning and rinsing away in the hot fall of water. 

The washcloth was a flimsy barrier. Rus could feel the pressure of fingertips through it, moving in slow circles, lingering.

Bad idea, such a bad idea, this was a terrible, awful idea…Rus caught Edge’s wrist, stilling his hand, felt him jerk in his grip. He turned enough to see him, half-crouched behind him, his bones damp and dripping. 

Rus swallowed thickly, tasting his own magic, and said, low, "don't do this if it's because you think you owe me something.”

"Can I do it if it's what I want?" Edge looked up at him, his eye lights were wide and hot, _wanting_ , ah, fuck.

"yeah," Rus breathed. 

Edge slid down to his knees, the washcloth dropped to their feet as his hands moved on without it. His fingertips were sharpened, a tantalizing hint of danger that had Rus catching his breath when they trailed along the outer lips of his cunt, smearing slickness. Before he could even adjust to that, Edge was leaning in, licking the trails of wetness up the insides of his femurs.

“watch the teeth!” Rus squeaked. Edge made a scoffing sound, but his tongue was almost excruciatingly gentle, teasing the soft folds, curling into long, soft licks. 

Garbled little sounds were already tearing loose from his mouth as Rus sagged back against the slippery wall of the shower. Desperately, he covered his mouth, stifling but not silencing them, and holy sweet angels, Edge was better at this than he would have ever guessed. His mouth was shockingly soft, little eager noises of his own escaping him as Edge moved to lap tenderly at the sore bones before ducking his head again, his tongue dipping inside Rus’s cunt as deeply as he could, finding and lingering on each tender place on the way.

This shouldn’t feel so good, it shouldn’t. It wasn’t like this was Rus’s first time with a face between his legs. Plenty of monsters had gone down on him, usually in grudging reciprocation; no one had ever groaned thickly against him as if this was something they wanted, panting softly against his drenched false flesh.

He couldn't recall anyone ever taking such care with him. Most of his encounters before this had been pretty rough and tumble, fun little one-night stands. No one had ever buried their face against him, making greedy, eager noises as their tongue slid over his clit, held his pelvis firmly to keep him from pushing in too hard and hurting himself on sharp teeth. 

That sweet pleasure was coming on too fast, too uncontrolled, and Rus stifled a shocked sob into his own hands as he came, Edge’s tongue pressing firmly to his clit, drawing it out until he was shaking, ready to collapse into the tub again for an entirely different reason. 

It was only Edge’s hands on his pelvis that kept him upright and when Rus opened his sockets again, still dazed and his cunt throbbing with dwindling pulses, Edge was looking up at him, his own magic glowing brightly at his pelvis and his mouth a smeared mess of orange magic that the falling water couldn’t reach to wash away. 

Rus slapped his hands away, sinking down and kissing him hard, tasting the sweetness of his own magic, the spice of Edge’s, and cupped his pubic symphysis, stroking firmly until Edge shuddered against his mouth, the hard length of his cock forming in Rus’s grip. 

It only took a light shove to topple Edge back gracelessly, his head thudding gently against the side of the tub. He didn’t protest as Rus straddled him, shaking hands settling at Rus’s iliac crests. “You don’t have to—"

“shut up,” Rus grunted, reaching between them to hold his cock steady as he sank down on it, grimacing at his soreness. The space was too cramped, his leverage was shitty in all this wet porcelain and cooling water pouring down him, but he needed this, he _needed_.

Edge was watching him, strained and trembling, “Are you..?”

“shut up,” Rus panted out again. “and let me…” He squirmed, whimpering as Edge slipped in deeper. “it’s good, it’s fine, i only…i need…” He slipped a hand between his legs, rubbing his clit, and yeah, that was what he needed, a reminder that this would be good, it was good.

Both of them groaned as Edge bottomed out inside him, their pelvises pressed tightly together. This was really the worst place possible, neither of them could really move, but Rus tightened his inner muscles, felt it from the inside as Edge gasped, hands scrabbling against him, trying to pull him down harder as he swore. 

This was going to be quick, Rus realized, dragging his fingertips from his clit to further back where they were joined, feeling the minute slide of Edge’s cock as it barely moved inside him. The sound Edge made at that touch was gorgeously tantalizing, thick and shocked and _needing_ , and Rus tried to rock his pelvis, tried to tighten his walls even more, shifting his fingers back to his clit when Edge let out a choking moan. Liquid heat, hotter than the water still falling down on them, filled him, the sudden surge made his own need splinter into ecstasy. Rus quivered with it, helplessly, so damn good, it was good, it was _perfect_.

Rus sagged down, resting his forehead against Edge’s sternum as he struggled to catch his breath. The water was turning cold, making him shiver, and come was starting to slide down his former clean femurs. Sharpened fingertips were gentle against his spinal column, moving soothingly and somehow that chilled him more than the water. 

What…what the fuck had they just done?

He didn’t even _like_ Edge, the whole point of this had been because Edge had needed help, not just an excuse to get off. 

“We should get out,” Edge murmured and dumbly, Rus nodded. He let Edge help him to his feet and rinse him off, wobbly as a newborn gryftrot, and stood mutely on the bathmat as Edge dried him, then wrapped him in a fresh, large towel as he dried himself. 

If there was something he should be saying, Rus couldn’t quite figure out what it was. Even as Edge led him back to the bedroom, all Rus managed was a weak, “i could really use a cigarette.”

Edge made a distasteful face as he stripped off the sheets, retrieving a clean set from the closet before he said, “If you open the window, you can have one.”

“really?” Rus said, blankly. Fucking around in the shower was one thing but Edge letting him smoke was on another level. He didn’t question it, digging his ciggies out of the bag, along with his lighter. “or i could’ve smoked on my way home?”

Instead of replying to that, Edge only raised a brow bone, shaking out a fresh blanket. “Will your brother be worried?”

By the opened window, Rus finally took a long drag off the cigarette, closing his sockets and almost moaning at the rush of nicotine. Fucking hell, he’d needed that. “nah i left a note…oh!”

He startled as Edge crowded up against his back. His fingers were gentle, stroking down Rus's bare spine. “Then why not stay a little longer?”

Um…what? He should really be getting dressed and getting the hell out. He could’ve gotten his clothes when he’d gotten his cigarettes instead of standing around in nothing but a damp towel, but Edge’s touch felt so good, making him reluctantly relax as he found tender places, working out the tension with a few careful rubs. 

“did you hurt yourself saying that?” Rus managed to make it sound teasing, swallowing away roughness as he lit another cigarette. “an hour ago, you told me to get the fuck out.”

“I don’t remember anything of the sort.”

The confidence in that made Rus burst out laughing, “that’s what you’re going with? blatant lying and denial? i gotta admire your conviction, but where have you been hiding this sense of humor?”

“In a box under my bed with the hearts of the children I’ve eaten.”

“Yeah, yeah, tough guy,” Rus pinched the cigarette between his knuckles, extinguishing it, and flicked the butt out through the bars. “c'mere.”

Maybe he could stay a little longer, he decided. He let the towel slide down to the floor, sighing as Edge pulled him in closer, his mouth already searching out the scabbed over bitemark on his collarbone and his tongue soothing over it. The sex had been incredibly good so far and he wasn’t _that_ sore. 

What could it hurt?

 

tbc

**Notes for the Chapter:**

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> 
> They do such incredible artwork and it is beautiful!


	6. Interlude

**Summary for the Chapter:**

> An interlude in the morning after, from Edge's POV.

* * *

Edge ignored the state of his home as he made his way quietly downstairs, careful to skip over the third step that creaked with enough volume to wake even an exhausted person sleeping in one of the upstairs bedrooms.

It took every bit of his already abused self-control to resist, but it was a necessary evil. If he began cleaning up the piles of crusted dishes and filthy clothes, he wouldn’t be able to stop until everything was back to its normal pristine state and for now, there were more important tasks to focus on.

First, he adjusted the thermostat to a more comfortable temperature for Monsters who didn’t feel as if the very marrow in the bones had turned to molten lava. Standing in his stocking feet and thin pajamas, even he was a little chilled. Someone else might find it unbearable even with layers of blankets. 

The kitchen itself was mostly untouched; of their carefully scrounged and repaired equipment, the only mess was a few dirty pans on the stove. Edge put them in the sink to soak and pulled out a flat griddle, letting it warm as he methodically mixed the batter. 

Their canister of flour was still mostly full, sugar less so. There was plenty enough butter left for frying and he cracked the two remaining eggs into the bowl, mixing it well. Pancakes were an easy and filling meal, and the last time they were in Underswap, Blue forced a small bag of vegetables on him. The tomatoes were a little overripe and soft, but he planned to slice and fry them anyway to add at least a little more nutrition to the meal. It was what they had, and it would have to be enough. 

Over the years, Edge had become an expert at making do. He could make reasonably tasty flour and water biscuits, topped with a thin gravy made from little more than bacon grease. Red willingly ate any hardtack so long as there was mustard to smear on top of it and perhaps a sprinkle of pepper. His brother still liked to eat cold soup or beans directly from the can. Making do, as they always had. 

These days groceries weren’t in quite so short supply. Years of culling the gang activity and shoring up the Guard had stabilized the supply lines and usually they managed well enough. He was Captain of the Guard and no one would have questioned if he was first in line for his allotment when the monthly provisions arrived in Snowdin. 

Nor did they question that Edge always chose to go last. Snowdin’s citizens only gathered their own allotment under the watchful eye of the Guard and scurried back to their homes although these days they don't hurry quite so much. Over the years, Edge had begun to note that occasionally there were unexpected extras left when it came to his turn; an extra bottle of mustard, a bag of flour, perhaps even a ration of meat. 

None of the residence of Snowdin thanked him for his service but words were a pitiful gratitude when there were other ways to demonstrate it. 

The first pancake rounds on his griddle were bubbling on top, the edges browned, and he flipped each one expertly, laying tomatoes along the sides to fry in the butter. Pancakes were one of the first things he’d ever learned to cook, the first recipe he’d ever seen. 

Books were difficult to come by in Underfell, particularly when searching for a specific genre. Edge hadn’t been looking for a cooking book when he found one. Sans…Red…had taught him to read from an early age, giving him lessons to work on while he was on his own during the day and his appetite for reading had grown along with his height. As a child he’d spent hours in the dump, hiding from other Monsters and searching for any reading material that he could find. 

The recipe book had been in surprisingly decent condition, only one corner soaked in water where the pages still tended to stick. The pictures had captivated Edge from the beginning. Foods that he’d never dreamed existed shone lovingly from the pages, vibrant photographs of dishes that glistened in a kaleidoscope of sauces. Right then, still crouched ankle-deep in filthy water, Edge swore he would learn to make these delights.

It was a promise he’d kept to himself, to some extent. His successes varied, generally based on access to supplies and how well he was able to substitute. These days he didn’t even need to look at the recipe book, he’d long since memorized it. His own notes were written carefully in the margins referencing substitution attempts with failures crossed out in a single sharp, black line. Adjustments that he’d attempted, his successes and failures all written out in penmanship that had gradually shifted from a childish scrawl to bold lines. 

He was perfectly capable of cooking with what he had and even what he didn’t, despite what the other universes seemed to think. 

Edge didn’t think about the one currently sleeping in his bed. Not the soft exhaustion visible in the darkened shadows beneath his sockets, nor the delicate, tempting lines of his bones, with outline of Edge's teeth still set into his collarbone, caked over with dark, rusty marrow. All of that was currently buried beneath blankets that were fragrant with the spicy-sweetness of their combined magic and the peculiar, lingering musk of heat. Hidden within the safety of his bedroom.

Instead, he thought about the others and about Blue in particular, his appalled expression the first time he’d seen Edge’s pantry. 

Ever since that day Blue had been scheming up ways to share their extra supplies with him, working around his objections. Red found it amusing, but then, he would.

The others all thought his refusals were about misguided pride and Edge had never disabused them of the notion. There was no explanation that would allow them to understand his reluctance wasn’t about conceit at all, but debt, and not in the form of G. They could never afford to be indebted to the others for more than they were able to repay, and Edge knew the price they would ultimately demand. 

Eventually, someone would ask them to leave their home. Leave Underfell and stay in one of universes that they considered ‘safe’, as though any such place existed. None of them truly understood, although Edge suspected Papyrus might if he tried to explain. 

The one currently asleep in his bed likely wouldn’t.

Nothing less than his presence and Red’s kept the gangs out of Snowdin, nothing else could keep these battered, suspicious people safe. He could no more withdraw his protection from them than he could part with his own soul. Underfell was his home, every dust-encrusted corner of it and he would defend it with all the HoPe he possessed.

The time would come where they would ask, and it would, Edge knew it would. Someday he would come to Underswap or Undertale, battered from a fight or with fresh LV glowing in his soul. That was when they would ask, no, demand that he and his brother leave Underfell. Edge always planned refuse, no matter how many care packages Blue forced into his hands. 

He couldn’t think right now about what he might answer if the one sleeping upstairs asked him, not now. Now he was making breakfast.

Pancakes were amongst the simplest of the recipes and a staple in their household. These ones were perfect, golden circles, slowly piling up on plates, and softly browned tomatoes at their side speckled with salt and pepper. A decent, filling meal. 

He heard a door open, but it wasn’t the bedroom. The clunking as a row of deadbolts was unlocked told him it was the front door. Through the kitchen door came the sound of Red kicking snow off his shoes in an effort not to incur Edge's wrath. Uselessly, but then, his brother would know that as well.

His wariness as he opened the kitchen door was wise; Edge could feel the prickle of ready magic in the air. He ignored it, focused on his cooking. His own magic was recovering but he didn’t reach for it, kept it focused on healing the soreness in his bones. 

“hey, boss,” Red crept close enough for Edge to see him out of the corner of his eye socket. He tucked his hands into his pockets, rocking back on his heels as he offered a cheeky smile. His attempt to look shamefaced lacked any believable sincerity. Hardly a surprise. “looks like you survived.”

“I did,” Edge said, evenly. He poured out two more perfect rounds of batter, the griddle spitting and hissing at the addition. “You need to leave.”

His brother was caught off-guard by that, that false smile shifting into a true frown, “huh? why?”

“Because I am angry enough to hurt you,” Edge told him. It was an effort to keep his voice level, and even so, there was a faint, audible tremor in it, “and you’re guilty enough to let me.”

Red licked his teeth, his eye lights darting around the kitchen. “he told you, huh?”

“He didn’t need to. We both know that there is only one reason he would have come to see me, don't we? Let’s not pretend otherwise.”

“it needed to be done.” The iron in those words was familiar from childhood, years of Edge believing that his brother knew best, and it was only as a teenager that he’d come to realize there were times when that was not true. 

“He should have had a choice!” Edge snarled. He exhaled slowly, staring at the pancakes until the sharp crimson haze over his vision eased. “Does he even realize the extent of what you’ve done?”

“did you tell him?” Red countered. Edge said nothing, didn’t bother pointed out that he’d hardly been in a frame of mind for discussion last night and this morning, ah, well, that had its own excuses. His brother was not about to turn this back on him, and he seemed to realize it. Instead, he only shrugged. “you ran out of time, little brother, so i chose for you.”

“I already made my choice, Sans, as you are well aware. I was choosing to go through it alone.” He turned around, leaning against the counter next to the stove. “You simply decided you didn’t like my choice and made your own. Well, congratulations,” Edge clapped slowly, mockingly, echoing in their small kitchen. “You didn’t just take away my decision, you broke my trust. I have always had you. If nothing else, I could trust you. You took that away from me and I'm not sure how to forgive you.”

That hit its mark. Red flinched and for once, there was no slick humor or sardonic amusement to layer over his true emotions. It left him with nothing but raw, stricken vulnerability and Edge had to turn away from it. 

He took the moment to flick on the coffee machine, the rich aroma rising, masking the lingering smell on Edge’s bones. He couldn’t fathom what his own heat scent had been like but the only smell clinging to him right now belonged to someone else. Almost cloyingly sweet, enticing, and it tickled at a certain urge. One that Edge ignored; he was no longer captive of his bodily desires.

“yeah?" Red managed finally, his voice cracked, rough and thick, "maybe i don't fucking care if you do or not. you're alive.” He licked his teeth, rubbing a hand over his head with a clatter of finger bones. “think i’ll stay at the inn another few days. bet the bed is still warm.”

“i think that would be wise,” Edge said, softly. His attention was back on the griddle, away from his brother.

“besides, you still fucking stink…why are you making so much food if you’re kicking my ass out?” Red asked abruptly. He stilled, his eye lights widening as he drew his own conclusions. “he’s still here?”

“He is,” Edge agreed. There was no point in hiding it. He added another golden pancake to each stack. 

Red’s eye lights shrank to pin pricks, “boss-“

“It’s too late. I tried to let him leave.”

“fuck,” he breathed. Good. Let him regret his actions, not that the punishment suited. He wasn’t the one who would have to deal with the fallout. Red never was, it was always Edge cleaning up his messes, only now, the mess was close enough to home that Red would feel the effects of it. 

“You knew there was a chance,” he told him, almost gently. “And you forced me to take it. You need to leave now.” 

His brother turned away. No apology for what he’d done but then, Edge hadn’t expected one.

“boss?”

“Yes, Sans,” Edge allowed the sharpness of his impatience loose. His brother needed to _leave_. 

“keep a hand on him when you tell him, or you’ll be talking to air. i know his kind, he’ll run.”

“Of course. I’m very familiar with his kind, myself. Brother, you need to leave _now_.”

There was a quiet pop of teleportation and Edge grit his teeth. The spatula in his hand snapped in half with a sharp crack, the hard plastic giving away beneath his grip. The agitated LV in his soul throbbed for a moment longer, hotly, demanding an outlet before it dulled sullenly, easing.

Edge threw the remains of the spatula into the trash. The pancakes were done, anyway. He took a moment to delve back into their meager stores and found a small bottle of honey, carefully drizzling it over one stack of pancakes with a heavy hand. Then he set both on a tray along with filled coffee cups and carried it upstairs.

In the wreck of his bed, the figure that was curled into the blankets stirred, sniffing audibly. Rus sat up with a groan and the agitated roil in Edge’s soul eased at the sight of him. He yawned and stretched, and though the look in his eye lights was wary, his smile was genuine and sleepy. The blanket slipped down enough to expose the healing bite mark. Tempting.

“please say one of those is for me?” Rus mumbled, reaching out with greedy hands.

“It is.” He settled the tray on the bed, nudging the honey-drizzled plate in Rus’s direction. Instead, he chose the coffee, swallowing half in one gulp. The pancakes didn’t wait long, Rus forked up a honey-sopped mouthful with his other hand and his groan was tantalizingly close to pornographic.

The satisfaction that came with watching him eat was disconcerting and expected.

Edge waited until the pancakes were mostly finished but before Rus could begin his faltering, elaborate dance of excuses and farewells. Then he said, with all the gentleness he could muster, “We need to talk.”

From the frozen, stiff expression that immediately fell across Rus’s face, it was going to be a long morning. 

 

-tbc-


	7. Chapter 7

**Summary for the Chapter:**

> Rus gets answers which is kind of a problem, since he didn’t even know there were questions.

* * *

Rus always enjoyed sex. The Underground could be boring as shit and that was a fact. A librarby of books and Napstatton on the tube at all hours didn’t change that, and a good, rousing bout of the pokey-pokey was a great way to kill time, helped to ease the pressure of a mountain pushing down on them. Plus, afterward, it put everyone in the mood for a nice, long nap. 

Really, it was a win-win. 

He had to admit, though, of all the sex he’d had, all the one-night stands, the afternoon delights, the quick morning-afters, no one had ever brought him breakfast in bed. Come to think of it, he couldn’t recall anyone bringing him so much as a cup of coffee, so for Edge to come up with a tray, loaded down with delicious-smelling things including the gorgeous aroma of liquid caffeine, well, this already put his bout of mercy sex above most of his other encounters. 

“please say one of those is for me,” Rus begged. He didn’t, quite, put it past Edge to bring up two cups of coffee for himself, even taking into consideration how their last bout of morning sex went; Edge pushing him with unexpected gentleness down into the blankets and maybe those teeth were sharp as hell but he sure as fuck knew how to use that mouth of his. 

It hadn’t exactly stayed gentle, either, not that Rus wanted to register any complaints.

His memory of the heat sex was a little blurry, swallowed up in the haze of pheromones. This morning? Eh, Rus could lie, but what was the point? It had been damn good sex, and Rus knew from past experience you didn't really have to like someone for that. The possibility of breakfast, now, that would raise Edge in his esteem.

“It is,” Edge confirmed, earning himself a shit-ton of unspoken accolades. He set the tray on the bed and nudged one of the plates at Rus. His eye lights were all for the coffee, though, and he snagged one of the cups, draining half of it in one gulp. The pancakes didn’t wait long, and Rus couldn’t help a groan as he took a bite of the honey-soaked stack. One thing no one could argue was that Edge knew how to cook; his pancakes were actually better than Blue’s, Rus could tell that much, even if he _was_ hungry enough to chow down on fried chunks of dog biscuit.

So, if he were keeping track, thus far Rus could mark down one night of heat sex, one surprisingly pleasant shower, one morning of extremely surprisingly good morning-after sex followed by a long nap, and a damn good breakfast. He was starting his day in the green, for sure. 

“We need to talk.”

Aaaaand, there it went, right back into the red.

“aw, man,” Rus sighed. Of course, Edge would have to go there. At the end of the day, everything had turned out okay, better even than he could have hoped. No dust pans required, good sex had been had. And now Edge wanted to open up his mouth and ruin it all. He should’ve known. Rus pushed a bite of pancake around the plate moodily, sopping up some extra dregs of honey. “you’re going to make it weird.”

That made Edge rear back a little, blinking in surprise, “What? I’m not going to make it weird. There are simply a few things we need to discuss.”

“see?” Rus said accusingly. “weird!” Damn the pancakes and coffee for tempting him, he should have ditched while he had the chance. He could have gone home, practiced a little careful repression, and moved on from all of this by the next movie night. Breakfast should have made him suspicious from the get-go. That’d probably been part of Edge’s plan from the beginning, tasty bait for the idiot who should have fucked off a few hours ago.

“I am not going make it weird!” Edge snapped. Like it wasn’t already strange, seeing that familiar constipated irritation while Edge was sitting there in his pajamas. “Must you...never mind, of course you must.” He took a long, slow breath, obviously bracing himself to make things weird.

Maybe it wasn’t too late to cut this off at the pass.

“look, i get that you’re probably feeling kinda ‘eh’ about all this,” Rus gestured vaguely at the bed with his fork, only just catching a drip of honey from falling on the sheets. “but it wasn’t really any of your fault, so tell you what. let’s just bury it all and plant a tree on it. doesn’t really need any talking about, does it?” 

Rus took another bite of pancake, because fuck it, they were already here. May as well enjoy his bribe. “i mean, this has been a lot of fun and all,” he winced the moment he said it, abort, abort, the plan was to _not_ make this weird. “um, i mean, not fun, it wasn’t as bad as i was expecting…not that it was bad! it was good, i…fuck, make my mouth stop talking.” 

This was why Rus never got breakfast in bed, he really was shit at the morning after.

Edge, who’d been sitting there staring at him while all those words came flopping uselessly out, said in that nerve-gratingly dry way of his, “Let me talk for a moment, then.” 

He slipped a hand beneath the blanket, curling it around Rus’s bare ankle. For a long moment, Rus didn’t get it, like, was ‘talking about this’ a euphemism for let’s go one more round? Because Rus was pretty sure his crotch wasn’t going to speak to him for week, at least. 

Then Edge added, “I want you to promise not to leave until I’m done. You owe me that much.”

That hand made a lot more sense, all of a sudden, a calculated move to keep him from shortcutting away. Fucking hell, this was all so…so Underfell, everything planned from the moment the pancake batter hit the griddle. Trying to fight loose would get him exactly nowhere, his little spat with Red proved that much, but the temptation to try was pretty fucking hard to resist. 

“i owe you?” Rus ground out. “that’s what you think? i helped you, you dick!”

“You did,” Edge agreed, and that made Rus’s growing anger falter. He hadn’t expected Edge to actually _agree_ with him. “But the fact remains that I did not ask for nor did I want your help. That leaves me in the unique position of appreciating what you did and still being angry that you did it. So, if you could please be quiet for a few minutes and listen to me?”

How was it that the fact that Edge wasn’t wrong only made Rus all the more pissed off? 

“fine,” Rus said, grudgingly. He pushed his plate away, tugging the blanket up a little higher since Edge obviously wasn’t going to let him go long enough to put on his damn pants.

Edge set his own empty plate back on the tray. “How much did my brother tell you about heats?”

Rus only crossed his arms over his rib cage and looked at him.

After a moment of silence, Edge said impatiently, “Well?”

“you told me to be quiet and listen.”

Edge closed his sockets and pressed a knuckle into the spot over his nasal aperture as if he was getting a headache. “Do you want to stay here all day discussing this or could we get it over with?”

“fine, fine,” Rus grumbled. He hoped that headache took over Edge’s whole skull. He hoped it was bad enough that _Red_ could feel it. Speaking of… “your brother didn’t tell me shit—" Rus stopped and gave Edge a narrow look, “how do you know it was red who got me here?”

Edge favored him with a humorless smile. “Who else would have sent you to check on me? It wasn’t difficult to narrow the pool of suspects.”

“fair,” Rus admitted. Wasn’t like anyone was going to post it to the Undernet, he supposed. _‘Tall, asshole skeleton, needs a good time in a bad way.’_ “anyway, he didn’t tell me anything that i didn’t already know. i found an old science journal in underswap, it gave me the gist.” 

Edge nodded. “And did that book of yours discuss bonding?”

“not…really?” Not that he remembered. He’d been a little distracted by all that info about biting and marking, but he was pretty fucking sure he’d remember something that sounded so ominous. 

The hand on his ankle tightened a fraction. Edge wasn’t wearing his normal gloves, the bone on bone contact scraped a little. “Technically speaking, any partner with the appropriate genitals can get you through a heat cycle. Most often the night ends with nothing more than a small scar and possibly a fond memory. But on rare occasions, there can be a…residual effect.”

“what kind of residual effect?” Rus asked suspiciously. 

The slow, deliberate way Edge was talking did not make Rus feel better about any of this. “There can be a certain level of commitment with an actual, truly compatible mating.”

“okay, yeah, you just said the bad word, i’m going to go home now.” But the grip on his ankle was implacable, almost painful, and Rus wasn’t liking his odds of fighting out of it. He wasn’t liking any of this, not a stars-damned word, and the pancakes, which should have settled nicely into his magic, were instead making it churn into something close to nausea.

Edge only kept talking, slowly and carefully, “Most Monsters can move on easily after a simple heat mating. But in some instances, the marking becomes a more,” he hesitated, then added, softer yet, “permanent bond.”

“please, stop.” Rus barely managed to whisper it, almost a plea, because he didn’t want to hear this, didn’t want to hear any of it, he wanted to go home, he—

“I can’t,” Edge said, and his gentleness was so much worse than any anger he’d ever shown. “You need to know this, because it’s going to affect you during my next heat.”

“your what now?” Rus said blankly. 

“My next heat. Since you didn’t catch pregnant, this will happen again.”

“um, yeah, i can’t get _pregnant!_ ” Every time Rus thought Edge had said the worst thing, he scraped up the dregs from the bottom of this fucked-up barrel and found something else. “my cunt is there for the entertainment value only!” 

“I'm aware of that, but until someone figures out how to inform my body, I’ll keep going into heat.”

Rus could only laugh, too-high and sharp, because it was starting to become very clear that, in the end, the joke was on him, wasn’t it always? “i’m not exactly a dick whisperer! red said the first one is the worst!”

“Yes, that’s true,” Edge agreed. “After a first heat, they aren’t as intense, and the chances of a mating bond goes down. But if you already have a mate, then the objective is reproduction. And the next time I go into heat, so will you.”

“what??”

Edge sighed impatiently. “What exactly do you think being mates means? The risk of bonding was always there; it started from the moment I marked you and finished with consummation.”

“i…” He hadn’t thought about it, what mates meant, and he didn’t have a fucking clue what bonded meant. “so, you want me to believe that a bunch of monsters are wandering around with some kind of mating bond in underfell?”

“Not at all. Most Monsters prefer to go through their heats alone rather than risking it and either survive or don’t. My brother’s first heat almost killed him.”

None of this made any damn sense, Rus hadn’t been hanging around with the science-types for a while now, but even he could see that. “so how the hell do you keep your population up if no one uses heats for what they’re for?”

He felt Edge’s hand flex on his ankle as he hesitated, his thumb moving in a circle as if trying to soothe, then with gentle candor, “That is not a question you want to hear the answer to.”

From what he’d heard of their King, Rus suspected it was true. He shook his head, trying to ignore where his own headache was starting to blossom. “no. no, no, no, i didn’t sign on for this!”

“Neither did I. We both know who signed us up for this.”

Any gentleness vanished with those words, gone hard and cold, and without even thinking, Rus blurted out, “don’t hurt him!”

That caught Edge off guard. He blinked, visibly surprised. “Really?” Edge sounded almost amused, certainly disbelieving. “He set you up and you’re protecting him? I was expecting you to demand his dust in a jar after this.”

Rus cringed. No matter how he felt about Red, he was still sort of wearing Blue’s face. He didn’t want that, never that. “he’s your brother!”

“That doesn’t mean I don’t understand what he’s capable of.” Again, that same little soothing motion of his thumb against his ankle, and Rus fought the urge to try and yank his foot away. “I am not about to hurt him. For what it’s worth, I’m sorry.”

“don’t. don’t apologize to me, i can’t.” Rus took a shaky breath and tried to think. This was all too much information, way too much, he couldn’t sort through it all. “i don’t understand. what makes you think we are having this ‘residual effect’?” He didn’t like that other word, didn’t even want to think it. “how do you even know you aren’t still just, i dunno, heated?”

Edge lifted his other hand towards him and then seemed to think better of it when Rus couldn’t help flinching. “I knew when I didn’t want you to leave. When I could feel you, this morning. Here.” He touched the center of his own chest, right over his soul, and it was all Rus could do to keep himself from yanking away and fleeing in a blind panic.

Not because he didn’t believe him, but because he did. Edge had no reason to lie and if he was saying they were going to be crotch buddies going forward, then it was the truth. But, fuck, he didn’t want to believe, he didn’t, he couldn’t.

His mouth seemed to be in agreement. “i don’t feel shit!”

“Not yet. I was the one in heat, I would be more sensitive to it. It will develop further over more matings.”

“no. no, no, no, no no, this was not the deal! i don’t want to feel you, ‘right here’!” He slapped a hand over his chest, hard enough for the bones to clack. The blanket started slipping and Rus caught it, yanking it back up. 

Edge raised his voice a little, talking over him, with that same calm, almost gentle tone. “It’s going to affect you more than that because soon you’ll start going into your own heats.”

Okay, what the _fuck_ —

“no,” Rus said flatly. “monsters from underswap don’t go into heat.”

“That would have been true before I put my magic inside you. Even if we hadn’t bonded, that much was going to be true.” A certain sourness twisted Edge’s expression. “Red could have warned you about that, at least.”

“put your magic inside me?” Rus laughed harshly, he had to laugh, this was all such a _joke_. “is that what we’re calling fucking now?”

“If it was only fucking, we wouldn’t have this problem. But like it or not, we’re bound together in this.”

“bound,” Rus said aloud, tasting the word. It was bitter, wrong, but that was the real word for it, wasn’t it? “okay, so you said you can ‘feel’ me.” Rus made little finger quotes, catching the blanket as it started to slip again. “so what, this bonding thing, what does it do? you feel what i feel, all that shit? read my mind?”

“Of course not, nothing so direct.” But Edge looked away, his eye lights sliding lower, down to the blankets.

“uh huh. and how does it do it indirectly?”

Softly, he said, “I can feel that you’re frightened." 

“uh, yeah, you don’t need some kind of fucking bond to know that. i don’t want to be bonded at all and sure as fuck not to someone who hates me!”

“I don’t hate you.” His free hand, resting on his knee, curled into a fist, hiding the sharpened tips of his fingers.

That was worth another laugh, “you’ve got a really fucking strange way of showing it! you’ve been an asshole since we met.”

“Yes. We aren’t good for each other. You infuriate me. You test me. But I’ve never hated you.”

“okay, stop,” Rus said unsteadily. “you need to stop.”

“And I believe the bond really isn’t as much of a problem as you’re thinking,” Edge said, a touch briskly. Like he thought somehow that they were winding towards the end and, oh, well, here’s how it is now, everything’s fine. “It’s hardly more than vague impressions, I expect you could get as much information from reading someone’s expressions. The point is supposed to be to form a closer bond to your mated to produce stronger offspring. A better soul connection results in offspring with higher HP and Magic levels.”

“this is so fucking stupid! why the fuck would we bond, we can’t _make_ offspring!”

Edge smiled thinly. He was still looking at the blankets. “I’m afraid you’ll have to take that up with evolution.”

“okay…okay…this is…this will be fine,” Rus said, slowly, as much to himself as to Edge. “we just need to fuck every once in a while, that’s all.”

“More or less.”

Okay, he could do that. What was a little sex from time to time, right, he already knew Edge was pretty good in the sack. Except— “what if i want to fuck around?”

“I wouldn’t begin to dictate what you do with your own body,” Edge said. As though he didn’t stiffen, that curled fist tightening with a creak of bone. “Mating is a biological function, not a marriage proposal. So long as neither of us are in heat, it shouldn’t matter.”

“yeah, that would’ve been more convincing if you unclenched your teeth.”

“The heat still hasn’t quite cleared my system,” Edge said defensively. “You smell—“

“i smell?” Rus groaned. It was something else to focus on and his mind snatched it up gratefully. “fuck, really? i can’t go home stinking like—"

“Enticing,” Edge finished. He looked up then, his eye lights sliding over Rus, lingering on his exposed collar bone where the bite mark was still healing, and Rus realized with sudden, cold clarity exactly why Edge was trying to keep his eye lights down.

“oh,” Rus said, a little blankly. And for a split-second, a wild surge of pure lust shot through him, from his soul straight down to his aching crotch where a sputter of magic made an attempt at a pussy before Rus ruthlessly squashed it. 

Bonded. Yeah. Now he was getting it.

“this wasn’t the deal,” Rus said, again, thinly, hating the whine in his voice, hating fucking everything. This was supposed to be a one-time gig, keeping Edge from dying, it wasn’t supposed to be this, not any of this. 

“I know. I’m sorry.” The real sympathy in Edge's voice only made it worse.

“i can’t—” _breathe_. “—think. i need to go. let me go.” It was closer to begging than Rus preferred but right now, he couldn’t give two shits.

“All right.” And maybe Edge was trying to say he didn’t hate Rus, yeah, whatever, but in that moment, Rus hated him. Because Edge knew he could let go, he _knew_ it. Because he also knew Rus couldn’t really get away from him. Not anymore. 

The very second Edge’s hand was off his ankle, Rus was gone, dragging the blanket with him down to the machine. With shaking hands, he inputted the code and went through the portal, stumbling over the trailing hem into his own basement.

He shortcutted right up to his own room, kicking aside socks and empty honey bottles to reach his bed where he curled up on the mattress in a sheet that still smelled like sex, his magic and Edge’s together. 

_Bonded._

Sleeping was more like self-defense and Rus didn’t try to think, not about anything. He only closed his sockets and let the world fade away.

* * *

tbc


	8. Chapter 8

**Summary for the Chapter:**

> Rus is dealing with all of this just fine, thanks. Denial is is a form of dealing and it's working so far.

* * *

The door to his room slamming open was not Rus’s preferred way to wake up. He was accustomed enough to it to only roll over with a groan, dragging the blankets with him. It was a fucking shame that shortcuts needed an end point, because right then disappearing sounded like a winner, winner, chicken dinner.

He buried his face into his ragged pillow, groaning, “bro, please.”

“Good morning!” Blue sang out and Rus peered out from beneath the blanket, reluctantly amused in spite his internal child pleading for more sleep. Rus was probably the only one in all the Universes who could see the vindictiveness past that bright cheer. Particularly when Blue went to the window and threw open the curtains to let the artificial sunlight pour in.

“blueeee,” Rus whined out. “you’re supposed to love and care for me, not torture me.”

“I love and care for you by not allowing you to sleep all day,” Blue scolded. “Wasting your life away in naps! 

“papyrus would have let sans nap.” Rus said slyly. As expected, Blue puffed up like a cat stuck beneath a rocking chair. He didn’t like comparisons being made between them, particularly ones that weren’t in his favor.

“Papyrus would have picked Sans and carried him to his station,” Blue said tartly. ”You’re just lucky I care too much about my spinal health. And anyway, you should have told me you were home, that note of yours was a little vague, don’t you think?”

“sorry, bro.” It wasn’t like Rus was about to tell him that he hadn’t been able to come up with a delicate way to phrase, ‘gotta go fuck Edge to save his life. bbiab.’

He’d gone with a simple, ‘back in a couple days, will pick up sock when return.’ Nice and vague. Especially since the untold story had picked up a few extra chapters that Rus hadn’t planned on. But Blue wouldn’t ask; he respected some boundaries and if Rus didn’t want to tell him, he wouldn’t push.

Just went to prove that Rus absolutely didn’t deserve his bro, but he was damn well keeping him anyway.

For all the sleep he’d gotten, Rus still felt tired, looking muzzily around the room. Scattered around were half-filled honey bottles, crumpled cigarette packs and dirty socks. Blue was very particular about the rest of the house but allowed Rus to keep his own room in a constant state of disaster without much fuss. His distaste was still obvious as he picked his way through the mess to the bed.

Whatever scolding plans were on the agenda were set aside when he got close enough for a good look. His stern cheer faded into genuine concern. "Are you feeling all right? Do you really need to lay down longer, honestly, don't get up if you're coming down with something."

"nah, bro, i'm fine." He was fine, absolutely fine. Maybe Edge was eating a little too much of the Underfell Cocoa Puffs because aside from being achingly sore, Rus felt perfectly fine. Not _bonded_ , thanks, not even a little.

He still wasn't really clear on what that even meant. Maybe it was worth going to see Undyne again, for a little more research for his ‘manga’? See if her little instruction manual had a footnote or two on troubleshooting.

But what was the point? It wouldn’t change anything and besides, he was a little low on bribery material to get through Undyne’s front door. And anyway, he really didn’t feel any different. Maybe Edge was wrong, what the fuck did he know about it, anyway? It wasn’t like there were studies on the effect of heat bonds between cross-universes constants or something.

Blue stripped off a glove and laid his hand against Rus’s forehead, all his cheer congealing into a fat ball of worry that he was preparing to toss right into Rus’s lap. Rus pushed his hand away impatiently. “i’m not sick, i’m just—” _bonded_ “—sore. guess i overdid it."

From his doubtful look, Blue wasn’t buying it and Rus couldn’t blame him. Overexerting himself wasn’t exactly the most believable story from his library and he didn’t really want to explain that it was actually the truth. But true to his nature, Blue rallied with a smile and didn’t poke his nasal aperture into what Rus could have possibly been doing to achieve any level of exertion, much less one that left him sore.

“Why don’t I draw you a bath then?” he offered brightly. 

“bro, that sounds like a fucking dream,” Rus said honestly.

“Language,” Blue scolded but his smile was indulgent. Before he could walk away, Rus caught hold of the hem of his shirt, yanking him back despite his flailing into a tight hug.

“Papy,” Blue complained. He snuggled in happily though, letting Rus take comfort in his brother’s presence.

It would be fine. He’d dealt with plenty of bullshit over the years, what was one more silly thing? Even if he did end up going into heat every few months, spending a night banging Edge wasn’t that bad in the scheme of things. All that crap about bonding was probably another load of Underfell bullshit that he could toss into the growing fertilizer pile. 

In the end, he let his brother draw him a bath, shooing Blue out of the room before stripping off his clothes. He caught sight of the bite mark on his collarbone in the mirror and paused, reaching up to touch the healing wound. The outline of Edge’s teeth was still clearly visible, and he wondered distantly if it would scar that way.

He sank into the water with a groan, let the heat leach away some of his aches and pains. It was gonna be all right and if he knew his brother, and he did, then there was going to be an extra-special breakfast waiting for him when he got out.

He really hoped it wasn’t pancakes.

* * *

For the next couple days, everything went back to normal. Rus stopped feeling like his legs were going to pop out of his hip sockets, spent his time playing sentry alongside sleeping too much, smoking too much, drinking too much and not listening enough to his brother scolding him about it. He didn’t get any weird or cryptic text messages, didn’t hear a peep from Underfell at all, which was just how he liked it. 

Aside from a couple of memes from Papyrus, he didn’t hear anything at all from any of the other ‘verses and when movie night rolled in that weekend, Rus decided his initial strategy of lemon-concentrated avoidance might be unnecessary. May as well give it a shot; it’d make Blue happy and, honestly, the Underfell brothers might not even show up.

Red in particular might want to stay away for a fucking year or so, and there was a bruise Rus didn’t really feel like pushing on right now.

Before anyone else showed up, Rus claimed the prime position on the sofa, lounging to watch as Blue puttered around. He stepped over Rus’s legs almost absently as he set up plenty of snacks on the coffee table.

A knock at the door heralded the beginning and Blue darted over to answer it.

“Hello!” Blue chirped eagerly. Papyrus and Sans stood in the doorway, and wasn’t language an interesting thing that allowed you to count Papyrus’s ruler-straight posture and Sans’s slump both as standing.

“hiya, short stuff,” Sans said easily, ignoring Blue’s visible outage. At his height, Rus was never gonna know the joy of taunting the only person an inch shorter than himself, but he couldn’t much blame Sans for indulging in it.

“hey, guys,” Rus called, drowning out Blue’s sputtering. “how’s tricks?”

“We have no tricks as we are not magicians!” Papyrus told him happily. “But we are doing very well as Monsters, thank you!”

“yeah, not doing bad,” Sans agreed. There was a covered bowl in his hands. “ _Monstered_ up the energy to get here, anyway.”

Rus grinned. “right to our front door, yeah, but your bro probably thinks that’s a _porch_ choice of words.”

“eh, maybe, but knowing we were coming here was a good way to get me _movieing_.”

“Sans! Would you please stop your incessant punning and give Blue our snack offering!” Papyrus scolded, snatching away the covered bowl in his brother’s hands. But his smile was sly as he told Blue, “I know that you always have plenty of food, but we brought something else to _in jest_! Movies do have certain snack requirements; I hope it’s not too _corn-troversial_.”

A knock interrupt them and whether it was delight at another guest or relief that it interrupted the pun-ishment, Rus didn’t know, but Blue lunged for the door, swinging it open with a cheerful, “Welcome!”

Oh.

Oh, fuck.

Edge was standing in the doorway. He wasn’t wearing his uniform, actually in jeans for once, his hands tucked in his pockets and he looked as constipated as ever but—

“Hi, Edge!” Blue said cheerily, not noticing his brother’s frozen stare. He held open the door for him to step inside. “We’re so glad you could make it!”

“Hello.” Edge nodded to him and the others. His gaze barely brushed over Rus.

“Oh, where’s Red?” Blue asked in dismay.

“He wasn’t able to come tonight.” He didn’t offer more, and there was more chatter, more greetings, but Rus didn’t really hear it. 

Everything was coming at him through a sort of fog, barely registering, and he was unable to tear his eye lights away from Edge.

Oh, fuck, he could _feel_ him. Like some kind of fucked up double vision only it was emotions laid over top of his own. 

They weren’t his, didn’t feel like his. Ghostly wisps of _wariness/ affection/ safety_ because Edge was fond of Blue, sure, felt safe in their home and Rus hadn’t known, he…he hadn’t…

He and Edge had never gotten along, rubbed against each other with all the friction of Velcro strips. Edge had less patience for puns than Blue and Papyrus put together, always griping at Rus and Sans for their lazy ways, an all-around fucking killjoy. But to think he was so tense in his own world that the first thing he felt in their home was _safety_ , fuck, that was—

For that first, frozen moment, Rus didn’t realize he’d stopped breathing. Not until an ache started in his chest, his magic starved for oxygen, and only then did he suck in a huge, painful breath.

His soul ached from trying to manifest even as he desperately kept it back. It felt like it was yearning towards Edge, like there was a chunk of it torn away and Edge held that missing piece.

Rus didn’t realize he’d made a low, whining sound until he noticed everyone staring at him with varying levels of concern. 

Including Edge, who looked coolly impatient but felt _worried/ concerned_.

“Papy?” 

He jerked wildly at the sound of his brother’s voice. Blue was standing right next to him and he hadn’t even fucking _seen_ him. His eye lights were soft, his concern visible rather than felt. “Are you all right?”

“yeah,” Rus blurted. He could feel a trickle of sweat running down the side of his skull and wiped it away on his sleeve, ignoring the tremble in his hand. “i just. i need.” He stood, fumbling in his hoodie pocket. “i need a smoke.”

Blue’s expression shifted to one of exasperation, but that underlying concern lingered. “You just had one!”

“i need another.” He almost stumbled on his way around the coffee table, taking the opposite side than Edge’s and flapped a hand at them. “go ahead and start the movie, i’ll be back before the credits are done.”

The cold air struck him as he stepped outside, cooling some of the roiling inside him. A cigarette helped more, and Rus blew out a slow stream of smoke, rubbing at his temples. 

Okay, that shit was not cool and if that was what ‘bonded’ meant then Rus wanted off at the next stop for this fucked-up train. How the fuck was that anything like normal, there was no fucking way anyone in Underfell was dealing with that shit on the 24/7.

The more he thought about it, the more Rus was convinced he had to have imagined it. Had to be. All his pointed repression of the past few days was coming back to haunt him like the ghost of a bad burrito at 2am. He just needed to deal for a couple of hours and then Edge would head home, and he could go back to his campaign of blissful ignorance.

Yeah, a couple hours was all. He could do this. Rus snuffed out his cigarette and dropped the butt into the can by the door. Took a deep breath to steady his nerves and stepped back inside. 

And froze.

Edge was sitting on the sofa on the opposite side Rus usually sat, Blue next to him and whatever the movie was, it wasn’t compelling enough yet for everyone not to look up at Rus. But there was only one set of eye lights that made him want to step forward, to reach out and take hold, pulling someone _(Edge)_ in. It was like a hook in his soul trying to pull him from the cool blue depths of denial towards Edge. Worse, he wanted to follow that compulsion, he wanted to be close to him, wanted.

Instead, he resisted it, ignored any voices, that fucking _concern_ and went to the kitchen. He slumped against the counter, his skull resting on his folded arms and that want only ached harder, sinking its teeth into his soul.

“Rus?” His name, all crisp syllables and more of that concern lapped over him. 

Rus whirled around with a gasp, stumbling back, his hands outstretched as if to hold it back. “don’t!”

“I’m not going to hurt you.” Edge kept back and sounded exasperated, all tight, curt words, but he felt, fuck, he felt _wounded_ , like seeing a face coming out from behind a mask.

“i know,” Rus gasped. He did, he couldn’t help knowing.

Edge took a step closer. “Then why are you afraid of me?”

He shook his head helplessly. Behind Edge, the doorknob twisted, but didn’t open, catching on the lock and Rus could only be grateful that Edge’d had the foresight to lock the door. 

“Papy? Are you all right?” His brother’s voice, muffled through the door, and Rus couldn’t deal with that, not now because Edge was coming closer to him, one slow step at a time.

“don’t touch me!” Rus pleaded, because he couldn’t, he couldn’t deal with this. Edge looked irritated, but that wasn’t the truth, it was a lie, all a lie, because Rus could feel it. The expression seemed like anger, but the emotion was _wounded/ worried._

“I want to help.”

“i know,” Rus managed, “i know, fuck, but please! don’t.” His sockets felt wet, dampness sliding down his cheekbones and Edge was right in front of him all that _concern/ worry/ concern_ and he wanted so desperately to lean into it. 

“All right,” Edge said, quietly soothing. “You’ll be all right. Listen to me, it’s hitting you hard right now because it didn’t have a chance to stabilize before you left. You need to control it.”

“how!?”

“Push it down.”

Rus only shook his head wildly “i can’t, i can’t, fuck, this—how can anyone live like this?” He couldn’t stop feeling him, it was all there in front of him, he couldn’t.

The knocking was getting louder and fuck, he didn’t want Blue to see him like this, didn’t want to explain, he didn’t. Edge frowned at the door, but didn’t answer the increasing loud calls from Blue.

“All right,” Edge stepped close and took hold of Rus’s upper arms. It was all Rus could do to keep from sagging into that touch. “Take us somewhere else.”

Rus looked at him in blank surprise. “you hate teleporting.”

It was one of his more hilarious memories after they’d all met. Rus was used to dragging his brother around and as far as he knew, Red and Sans did the same. So, the one time he’d been in a snit because Edge stole his favorite seat, Rus hadn’t hesitated. He’d teleported them both outside and he’d meant to go back in immediately to take his seat back. Only to stare in shock as Edge fell to his knees and vomited magic into the snow.

Since he wasn’t a complete asshole, he ended up let Edge have the disputed chair amidst a firm scolding from his bro. The only good thing that came out of it was the knowledge that he shouldn’t do that again and that Edge didn’t puke on either of their shoes.

This time the pulse of emotion matched Edge’s exasperated glare. “I’m aware of that. Would you rather have your brother as a chaperone for this? I’ll be fine, it’s not as bad when I’m expected it.”

Yeah, no, someplace else suddenly sounded like an excellent plan. Rus closed his sockets and focused, taking them both to a far, hidden corner in Waterfall.

The moment the void cleared, Edge staggered away from him, breathing deeply, and Rus almost fell to his own knees as he was swamped by nausea that wasn’t his own.

Holy fuck, if that was what teleporting felt like for him, Rus wouldn’t be doing it unless he was in danger of losing a limb.

It eased off quickly and Rus sank down on the bench as the nausea was replaced again with _concern/ worry._

“All right,” Edge sat down next to him. “Now listen to me. Can you feel it?”

“yes,” Rus gasped wetly, close, Edge was so close, too close, and he wanted to touch, wanted to get closer, wanted—

“Now imagine putting a wall around it.”

Rus shook his head desperately. He couldn’t, he didn’t want to, “i can’t.”

“Yes, you can,” Edge said firmly. “I want you to picture it. Putting up a wall, brick by brick, surrounding it. Blocking everything on the other side until it’s only you inside it.”

Listening to that low, soothing voice, Rus pictured it. One brick after another, walling off emotions that weren’t his own and eventually, it was gone, blocked off and away. 

Rus took a long, shaky breath and only then realized he was sitting hunched forward, his skull in his hands. His clothes were clinging to him sweatily and he felt like he’d run from the ruins to New Home.

There was a cool hand on the back of his neck, a thumb rubbing circles on his cervical vertebrae, but no emotions came through that carefully soothing touch. Shaky as he was, the only feelings he had were his own and he could shake that hand away without feeling the urge to chase after it for more.

“thanks,” Rus said grudgingly.

“You’re welcome, but I can’t claim my motives as entirely altruistic.” Edge leaned forward, his elbows on his knees and his hands hanging loosely between them. This little alcove in Waterfall was secluded enough that Rus had never seen anyone else and had no idea how the bench even got here. He came here a lot, his secret little place and in his panic earlier, he’d come to his safe spot. It felt strange to have Edge here with him, of all places, even as Edge went on. “Having a front row seat to your panic is the exact opposite of a relaxing evening out.”

“that’s fair.” The aftermath was aching in his skull like a Monday morning hangover, but Edge didn’t look any more or less constipated than normal, what the fuck. “how are you so much better at dealing with this?”

“Perhaps I’m simply more accustomed to dealing with situations that can’t be changed.” Edge smiled thinly. “Or perhaps it’s because one of the only readily available pieces of literature in Underfell is a manual on dealing with heat issues.”

“that’s not fair. i had to hit up the black market library for mine.”

“I’ll get you a copy if you want.”

Silence between them. For a moment there was nothing but the endless burble of water.

“why is this happening? why us?” If they’d been anywhere else, still sitting in the kitchen or Edge’s bedroom, anywhere, Rus wasn’t sure he could’ve asked. He didn’t want answers, he wanted it to go away. But sitting here with Edge next to him in his secret place and the memory of his concern fresh in his mind, along with the touch of his hand soothing on his neck, eh, may as well.

Edge didn’t say anything at first, only shifted to cross one leg over the other, staring out at the rippling pond. Finally, he said, slowly, “I don’t know. There wasn’t much study done on why certain Monsters were compatible with bonding. At least not in Underfell. But…Monsters aren’t meant to be solitary. Our souls crave others of our kind. Perhaps bonding was an evolutionary way to ensure it.”

It was a hell of a speech, but somehow, it didn’t sit right. It felt a little off, like it was one sidestep away from the truth, but Rus didn’t know how to say that without making it seem pissy. Arguing was dead last on the list of things he felt like doing right now, so he only said, lightly, “thanks professor, let me know how your thesis goes.”

Edge didn’t crack a smile but there was the faintest perception of amusement. That, at least, Rus could handle.

For a brief second, he remembered being in Edge’s bed, his gentle care even when it melted into eagerness, the pleasure of it, and almost Rus was tempted to lean in and take a kiss, see if that mouth tasted like he remembered.

He tossed another brick on that urge, squashing it flat. Fuck knew if this heat thing worked out the way Edge said it would, he’d get his chance.

The longer they were here alone, the more Rus wanted to be anywhere else. “ready to head back?”

“I think I’d prefer to walk. Fighting back nausea once is enough for me.”

“great!” Rus said cheerily. “have fun with that.”

He didn’t wait another second, already shortcutting away before Edge could protest. He didn’t go far, stayed close enough to hear Edge snarl his name, his exasperated muttering. But Rus hung back, hidden around the corner to make sure Edge solved the puzzle of how to get to the main path. The walk home wouldn’t take him long once he found it, Rus just wanted to make sure he headed the right way.

Maybe Edge could feel him there, he didn’t know. But he sure as fuck couldn’t feel Edge and that suited him fine.

* * *

-tbc-


End file.
